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Page 1 - LabLINK November 2011
LAB L.I.N.K.
Official Newsletter of Queensland Education Science Technicians Inc. (Q.E.S.T. Inc.) PO Box 6438, Gold Coast MC QLD 9726
www.qest.org.au ABN – 74 766 276 412
NOVEMBER 2011 VOL 19 NO 2 Hi All, There goes 2011. We hope the year has been a good one for you all and that you feel you have deserved the impending summer vacation. The variety of the work we do certainly banishes boredom. The opposite is often the case when we have to juggle multiple activities, deal with questionable teacher ability and students’ demands. It would be great if the teachers we support show their appreciation. A little pat on the back goes a long way to push those periods of frustration into the background. Just in case your staff neglect you ...
Congratulations for another year of
service, delivering quality educational
experiences across the whole gamut of
abilities. Due to unfortunate events, the positions of Vice President and Secretary are vacant. Contact Mandy if you would like to volunteer your time. The next big change in education will be introduction of the Australian Curriculum next year. What impact will this have on us? There really should not be much change, just aligning all the states so we are all teaching the same topics. As you may recall, it has been QEST policy to send two committee members and two general members who have contributed an article for publication in LabLINK, to Labcon in Melbourne every two years. At a recent committee meeting it was decided to alternate the Labcon experience with a trip to New Zealand for ConstaNZ. ConstaNZ is a 3 day
conference conducted on alternate years in a different city each time. This year ConstaNZ was held in Dunedin and previously at Auckland, usually in a boarding school so accommodation is on site. You may think you have nothing to offer other members but there is a wealth of experience among us; a speciality of yours, a method you have worked out to overcome a problem, a storage system you find user-friendly or even how you have managed to implement a change by insistence and persistence. That which is easy and commonplace to you may be a valuable piece of information for others. So, get those fingers a-tapping, photograph your favourite innovation and email your articles to either of us. We wish you all a restful or exciting break, whichever you prefer and a very happy Christmas. Jill and Wendy
CONTENT Committee President‟s Report Far North Queensland Network Meeting Surfing Science Hints & Innovations Agar Plate Disposal Photosynthesis Prac Hydrogen Debate Miracle Sweet Berry Snake Display End of Year Science Activities ========================================
The next meeting will be held at QAHS, and on Illuminate on Monday 30th January 2012
===============================
PAGE 2 3 5 6 7-11 11 13 14 16 17 18-19
COPYRIGHT NOTE. Articles for publication in „LAB LINK” should not have been published elsewhere excepting that, all articles submitted for re-publication, and any published material quoted in any article, be accompanied by a signed release from the COPYRIGHT holder. QEST Inc retains COPYRIGHT on articles that are published in “LAB LINK”. Written applications for non-commercial release should be addressed to: QEST Inc . PO Box 6438 Gold Coast MC QLD 9726
Page 2 - LabLINK November 2011
QUEENSLAND EDUCATION SCIENCE TECHNICIANS Inc. 2011 – 2012 COMMITTEE
PRESIDENT MANDY TIMMERS Queensland Academy Health Sciences, PO Box 1115, Ashmore 4214 Ph 5510 1217, fax 5510 1130 [email protected]
VICE PRESIDENT
TREASURER VICKI JORDAN Varsity College, Varsity Parade, Robina, 4226 Ph 5562 3575, Fax 5562 3570 [email protected]
SECRETARY
MEMBERSHIP CO-ORDINATOR HILARY GOETZE Pacific Pines SHS, PO Box 380, Helensvale 4212 [email protected]
WEB MASTER DEB COOK Tin Can Bay P-10 SS, Schnapper Creek Rd, Tin Can Bay 4580 Ph 5488 1222, Fax 5488 1233, [email protected]
ASSISTANT WEBMASTER REBECCA SMITH Livingstone Christian College, PO Box 420 Ormeau 4208 Ph 5546 7038 FAX 5546 7653, [email protected]
LABLINK EDITOR JILL CLOTHIER Caboolture SHS, Lee St Caboolture 4510 Ph 5498 0111, Fax 5498 0100, [email protected]
LABLINK EDITOR WENDY SHEARER Bray Park SHS, Lavarack Rd Bray Park 4500 Ph 38816627, Fax 3881 6600, [email protected]
REGIONAL REPRESENTATIVE DAVID WILD Channel College, Gladstone [email protected] ,[email protected]
REGIONAL REPRESENTATIVE Christine Murfin Marist College, Emerald [email protected]
COMMITTEE MEMBER JANE SKELTON Helensvale SHS, 243 Discovery Drive, Helensvale 4212 Ph 5573 8526, [email protected]
COMMITTEE MEMBER JAN McGAW Ferny Grove SHS [email protected]
COMMITTEE MEMBER BECKI COOK Queensland Academy Health Sciences [email protected]
COMMITTEE MEMBER GARY HUNT Wynnum SHS, Peel St Wynnum 4179 Ph 3906 7333 ghunt32 @eq.edu.au
COMMITTEE MEMBER JILL SMITH Varsity College [email protected]
COMMITTEE MEMBER NIKKI BRADFORD Harristown SHS, Toowoomba [email protected]
COMMITTEE MEMBER LORRAE BROADLEY Mt St Michael‟s College [email protected]
Your committee is there to deal with any queries you have. As a member you are welcome to
attend meetings of QEST. Meetings are conducted on Illuminate.
Contact President Mandy [email protected] and she will add you to her contact list. And send
you the password necessary.
Are planning a move? Will your contact details change?
If so, you need to contact Hilary Goetze and tell her or your LabLINK may not be able to
find you.
Hilary Goetze (Membership Co-ordinator)
Pacific Pines SHS, [email protected]
Page 3 - LabLINK November 2011
President’s Report November 2011
Hello Everyone, Term 4 is just about done and Christmas is upon us. It has been a very busy year for all of us. As I reflect on QEST’s year, I have begun to realise just how busy we have all been. The following is just a sample of what our members and committee have been up to:
Disaster recovery from floods and cyclones
Cheese making workshops
ConQEST 2011
Sponsorship of the School Amateur Wine Category at the RNA show
Union negotiations with EQ regarding progression
Regional PD- Far North Queensland , Sunshine and Gold Coasts and Toowoomba
National Professional Standards for Laboratory Technicians
Operation Archimedes
Certificate IV in Laboratory Techniques through RTO Symbio Alliance From this brief list you can see that QEST is looking at the wider picture and encompasses activities at local, regional, state and national level. This broadminded approach provides significant benefits to our members and provides opportunities for improvements in our work conditions, professional development and recognition, skills and knowledge and sense of community. As President of QEST, I would like to thank the members and the committee who help to support this organisation and its members- WELL DONE! As we head into another academic year, we have some significant changes coming online. These include the National Curriculum and Flying Start Pilot Programs. In addition, the new Workplace Health and Safety legislation and the Global Harmonisation of Chemical labelling and naming will come into effect. These will result in major operational changes and workload readjustments. During this time, please ensure you are kept well informed by your workplace and make yourself a priority- change can be stressful and your health and well-being is important. Finally, happy holidays! On behalf of the QEST Committee, I wish you all a safe and happy holiday period and I look forward to working with you in 2012. Kind regards Mandy Timmers President QEST
Page 4 - LabLINK November 2011
Subscribe to LABBIES LABBIES is the email discussion list for education Lab technicians. It is an essential tool for gathering information on any topic related to your job. To Subscribe send an email to [email protected] with subscribe LABBIES in the body of the letter and nothing in the subject line. you will receive two emails from listserv, follow the instructions to confirm your request. To Unsubscribe: Send an email to [email protected] with signoff LABBIES in the body of the letter and nothing in the subject line.
To access the archives of
LABBIES Discussion list
http://education.qld.gov.au/archives/la
bbies.html
Follow the prompts and you will
receive a password to use. The
archives are only available for 12
months – space constraints
Visit our web page www.qest.org.au
You have received you login and password
The web page includes committee contacts, minutes of committee meetings, links to suppliers,
links to Animal Ethics and more.
Naughty bits in focus! Western Histological has been manufacturing prepared microscope slides for over 21 years, supplying the
secondary and tertiary education sector Australia wide. Apart from the usual plant and zoology products Western
Histological’s human histology slides which have recently been used to establish a number of new medical and
para-medical courses in several universities. Human reproductive system slides are also popular in schools –
here’s a sample:
H 773 Penis, t.s.
$12.00 ea
H 775 Spermatozoa, w.m $6.50 ea
H 754 Ovary, v.s. $6.60 ea
H 764 Lactating mammary, v.s. $6.60 ea
Over 120 other human histology slides are available. Please visit the website for more information.
Western Histological Brett Cockman, Proprietor
19 Lefroy Road, Mt Nasura WA 6112 Mobile: 0407 996 077 Fax: 08 9390 5175
Website: www.westernhistological.com.au E-mail: [email protected]
Page 5 - LabLINK November 2011
Below is a photo of Maria showing us some of her new, well organised storage and Kylie in her fairy wings!
Far North Queensland Lab Technicians Networking Day Michelle Sambells & Michelle Graham, St Marys Catholic College, Woree
Earlier this year Kylie Azzopardi from Tully SHS took the initiative to organise us Far North Labbies into a much needed get together to network and exchange ideas. Patricia Tahir and Maria Posselt from Mareeba SHS kindly offered to host the event and to give us a tour of their beautiful brand new labs to boot. The day started with a spot of “shopping” as Tricia and Maria shared a haul of unwanted goodies from The Mareeba DPI including volumetric flasks, filter paper, conical flasks and much more. Once everyone had secured a stash of goodies we had a who’s who introduction and a general discussion about Risk Assess. Nearly everyone who had Risk Assess loved it and felt that it made risk assessments and laboratory scheduling easy and the new CARA regulations less daunting. Next it was time for a delicious morning tea of cream buns and cakes courtesy of QEST (thank you QEST!). At this point Kylie decided to explain why she had arrived sporting a lovely pair of pink fairy wings! She had recently attended a PD which we think was all about being positive and outrageous although we could be corrected on that. Kylie also enlightened us about Greg Young and Project Archimedes, through which she had gained some spectacular equipment which was no longer required by various government departments. Next up was a trip to the new auditorium for a session on Chem Gold III. Unfortunately technology beat us and we were unable to get CG3 to load on the big screen (someone commented that that said it all for CG3!) all that we could muster was the impending molecule of doom! Some of the more computer literate were able to help others with specific CG3 problems but the general consensus of opinion was that a CG3 training day was much needed in the North and thankfully Kylie is already onto this. Julie Norman from Mossman presented her idea about doing a chemical disposal ‘roundup’ whereby one company could visit all schools to collect their old chemicals and provide a more cost-effective service. This idea was well received and is being progressed. Many other mutually beneficial discussions were held and other topics covered included: CONQEST and how beneficial it was to those who were able to attend - remember all staff is entitled to 2 days of job specific training per year. CARA and its effect on school excursions. Vented chemical storage cabinets. Bunsen burner and acid trap checks. All in all the day was a resounding success and a big thank goes out to Kylie for organising, Tricia and Maria for hosting and not to forget QEST for the morning tea! Attendees: -
Julie Norman – Mossman SHS,
Kylie Azzopari & Wayne Morris - Tully SHS,
Michelle Graham & Michelle Sambells – St Marys
CC,
Leanne Gibson - Trinity Bay SHS,
Jo Nucifora – Gordonvale SHS,
Karin McKirdy – St Andrews CC,
Chris Weller – Peace Lutheran College,
Patricia Tahir & Maria Posselt – Mareeba SHS,
Jocelyn Goodwin – Atherton SHS,
Fred Stevenson – Redlynch SHS,
Karen Wilkinson – Malanda SHS,
Mikayla Curtis & Debbie Parsons – Bentley Park
College.
Page 6 - LabLINK November 2011
Solar/wind/water generator building
http://www.re-energy.ca/docs/wind-turbine-cp.pdf This site provides information, construction plans for methods to generate electricity from alternate sources, also includes questions.
Chemistry experiments for schools http://practicalchemistry.org/experiments/introductory/category.html This site provides chemistry experiments that have been modified and described in sufficient detail to be successfully used in the school environment. Also are provided notes about teaching and learning, and a few web-links. The site is particularly useful for teachers and technicians who wish to develop their practical skills in chemistry. You can sign up for an electronic newsletter to take advantage of further resources as they are developed.
Biology aminations http://www.medtropolis.com/VBODY.ASP great website with interactive tutorials & animations about the brain, skeleton, heart & digestive system.
http://www.johnkyrk.com/ cell biology aminations
How to get stopper out of bottle http://www.youtube.com/watch?v=aKhOG7duR9k
Analytical Chem lab tech resource http://delloyd.50megs.com/
Youtube macro-invertebrate movies Bacteria http://www.youtube.com/watch?v=rf4vFQSIXMY Euglena http://www.youtube.com/watch?v=0rNI8Bos_BQ
http://www.youtube.com/watch?v=F-0ch_Z1f50&NR=1 Paramecium
http://www.youtube.com/watch?v=FNTanYlNcRE http://www.youtube.com/watch?v=saLYHUs6cWk
Amoeba http://www.youtube.com/watch?v=1iuv2Lr1T5A
Vorticella
http://www.youtube.com/watch?v=z_tvLljH8t0 Euplotes
http://www.youtube.com/watch?v=M87vzSz-uTU Hydra
http://www.youtube.com/watch?v=yqXkaZwiu6s http://www.youtube.com/watch?v=9MEt0Ot7Pkc
Daphnia heartbeat http://www.youtube.com/watch?v=ibDwYghgb2k
Page 7 - LabLINK November 2011
Snake skin preservation There is a snake at school as a pet called Mr Carroll’s and I look after him. He is now 8 years old. I keep his skin laminated in a panel together with the date the shed happened and how long it is, in order to follow his growth. You can see in this photo taken from the wall in the prep room, just behind my computer, right now. Eliane Costa, Science Laboratory Technician, Stuartholme School
Water Baths Cheapest and most versatile option is to use hotplate with 250ml beakers We set up several stations with different temperatures. Each group can have their own beaker at a temperature station...labelled beaker (group) labelled test tubes reatment...etc. Can do 0oC too with ice + salt bath in ice-cream container Peter Harley , Science Operations Officer , Benowa SHS
For years it's driven me nuts that when using waterbaths and small beakers, some invariably tip or get knocked over in there and if the beakers contain milk or similar any spillage means
emptying & cleaning the bath before it can be used for the next lesson When asked to prepare the junket prac, I was determined to have clean waterbaths at the end of it so I played around with a few things & came up with this: It cost $10.90 for a huge piece of polystyrene from Clark Rubber, & I found the short length of downpipe from Bunnings to cut the holes for $1.99.
Just cut the styrene to rough size with a hot knife, trim for a snug fit inside the waterbath, then heat the piece of downpipe in a bunsen & cut a few holes at a time. Took about an hour to do 4. 6 classes have used it so far & no spills
From Chemtalk Forum
Rhoeo -Additional information on the marvellous rhoeo. To observe beautiful stomata, it is not necessary to do a leaf tear. Simply break off a piece of leaf, mount it on a microscope slide and observe under the microscope. The stomata a clearly visible and the natural pigmentation gives excellent definition. Eliane Costa, Stuartholme College Use the same technique with a begonia leaf, there are 4 stomata per cell.
Silver nitrate management We get the students to wear aprons, safety glasses and gloves and only use 0.1 M silver nitrate for most science classes. A bottle is placed on the front teachers bench on a large tile and each group comes up and gets a few drops to add to their test tube or spotting tile. Our lab has a spill kit with a spray bottle of 0.1 M sodium thiosulphate for silver nitrate spills. In senior chem one of the unknown substances is usually silver nitrate. We tape plastic garbage bags to all the lab benches apart for the one bench without a garbage bag if using a Bunsen burner. Julie Lisle, Xavier Catholic College, Eli Waters
Page 8 - LabLINK November 2011
Potometers, a simple
Hydrogen gas generator Add bits of aluminium to sodium hydroxide solution, wait a little while then the reaction takes off. Note – the reaction will produce a bit of heat as well and can get very hot producing a lot of steam. Roll some cigars of aluminium foil using about a A5 size sheet of alfoil into a cigar shape. This makes it convenient to add more aluminium to the reaction flask as you need them, one or two cigars at a time. I will use about 500mL of 1-2M NaOH (20 to 40g NaOH in 500mL water) solution (does not need to be accurate) in a 1L schott bottle that can handle the heat. The more concentrated solution will have a greater capacity for producing hydrogen gas. The steam produced will be caustic so this should be “scrubbed” by bubbling the gas produced through a water scrubber. Look at the picture to show how I set the system up. I use this when I produce the hydrogen for a “singing Pringles can” demonstration. Note that the scrubber has the inlet tube just below the water surface so that the gas bubbles in the water. If it is too far below the water surface, a lot of the scrubbing water will siphon back into the reaction bottle when all the aluminium is consumed and the flask starts to cool down. Pull the stopper from the reaction flask as soon as the hydrogen gas stops being produced to prevent the back siphon. Matthew Stuart, All Hallows College
Electrical leads Have you tried the trick of NOT stripping the insulation off the end of the wire? (an electrician showed it to me!). You just cut the wire off flush, and insert insulation and all into the hole and screw the screw down really tight. The screw will penetrate the insulation to make contact with the wire, but clamping down on the soft insulation rather than the hard wire tends to hold the wire in much more firmly, with less chance of the screw working loose. Saves the bother of stripping the wire too, although it is probably a good idea to check each wire as you complete it (with a powerpack and
light globe) to make sure that the screws have actually broken through to the wire.
Oil layer
water
Plant
cutting
Page 9 - LabLINK November 2011
Stopper Preservation Storing rubber stoppers in the fridge - I’ve done that for stoppers, pipette bulbs, hosing, balloons etc. for many years. The staff still laugh at me. Tracy John Ellis, Science Technician, Assisi Catholic College
Nutrient Broth pH Taken from “The Laboratory”
Christina Rassmussen, Science Operations Officer, Bundaberg North State High School
Mitosis – more hints Having problems producing good root tip squashes? I find the stain stock solution does not last from one year to the next but should last for a couple weeks. It could have been old stock from your supplier also. Secondly if your acid bath is too hot or you leave the tips in it too long you "destroy" the cell structure and will have problems with the stain. I find the heat from the microscope lamp bulbs also has the same effect if the slides are on the stage for a long time. My notes say to harvest root tips early in the morning (around sunrise) and to store them in the fixative in the fridge only if you need to. Best results are from unstored tips. Australian garlic is what we use for root tips. Christina Rasmussen, Science Operations Officer , Bundaberg North State High School You only need the first few mm’s behind the growing tip, so the roots do not need to be too long. Get rid of the existing root rubbish so you get good new growth. Onions, garlic and eschallots work – most opt for garlic, but I had better results with eschallot even though they are a bit slower. It’s getting warmer, and they do better in cooler areas, so try them in a fridge or shaded area. I cut the top off a coke plastic bottle – at the point where the ‘shoulders’ meet the ‘waist’. Invert the top so it nestles inside the rest without pushing in. The onion/garlic/eschallot sits in the top (neck), and you add water in the base till it just touches the root area. Its easy to see what is happening, adjust water etc. No need for toothpicks. Allow a couple of weeks to make sure you get what you want Tracy Ellis
Flame Tests Soak whole Paddlepop sticks in water, dip in a small quantity of the powdered chemical. Better colour. Less mess and work. Tracy Ellis
Page 10 - LabLINK November 2011
Agar short cut You don't need to spend time heating the water or melting the agar. Just make it all up cold, give it a really good stir on the magnetic stirrer, pop it into your pressure cooker or autoclave and let it do the work of dissolving and melting things. Leave the magnetic stirrer in the bottle. When it's sterile put it back on the magnetic stirrer and give it another really good whiz. It can sit there stirring away until the bottle is cool enough to pick up and then you're ready to pour. You should have agar ready to pour in about an hour. Deb Cook, Tin Can Bay SS I wouldn't bother with pressure cookers, I would go straight for a steriliser. I can highly rate Siltex 17L autoclave. No fancy dump tanks, printers or rinse tanks. Livingstone sell them for about $5000. Well worth it. Make sure it fits a 1L shot bottle, 2L if you can. Just mix agar and water, shake the bejeezes out of it and put it in and cook. Let the temp come down to 50 degrees and dispense. All done in a very short amount of time. Actual working time is about ten minutes. You don't need to be around for the sterilising. Hope this helps. Kylie Azzopardi, Tully State High School
Stoppers – inserting tubing
I used to use oil to lubricate the tubing but didn’t have any handy today. So I tried WD40. Sprayed the hole and the tip of the glass tubing. The glass tubing slipped through the stopper easier than ever before.
Karin McKirdy, St. Andrew's Catholic College Good improvisation. Water is good too. You may also like to try first inserting a cork borer of slightly larger diameter than the glass tubing into the hole in the stopper. Put the glass through the borer then withdraw the borer.
Gary Hunt You can also use a drop of undiluted detergent, silicon grease or glycerol, and unlike oil based lubricants they won't cause the rubber to perish.
Jenny Parker, St Joseph’s College
Video Microscope upgrade Do you have a video camera that attached to a microscope that plugged into the now superseded television? We recently purchased an adaptor to connect the camera to the USB of a computer. Jaycar had a choice of 2, $79 and $49. We chose the Digitech USB Video & Audio Grabber for $49. It was not happy to capture images to Windows 7. Fortunately the computer techs had an older laptop with Windows XP that we were able to commandeer.
Carbon dioxide – measuring production Use a datalogger and a CO2 gas probe. 1st get the kids to breathe out into an empty freezer bag, and then insert the probe and read the CO2 level. Then get them to hold their breath for 45 seconds (or longer) and breathe into a bag & read again. Then get them to run - up & down stairs or whatever - and breathe into the bag again, and the CO2 level should have changed significantly.
Burnt sugar on glassware Problem solved with strong soln of NaOH...worked on burnt jelly crystals stuck to evaporating dishes as well which I’d stored in my cupboard to attack later at end of term so all good! Marilyn Beattie Try denture tabs (I use the cheap Homebrand). 2 tabs in 500mls water. Soak overnight. Peta Perry
Page 11 - LabLINK November 2011
Drying agents Drying agents are generally inorganic compounds used for removing water from organic syntheses. They can also be used for removing water from gas samples to some extent (including ‘damprid’ in closets). Saturated aqueous sodium chloride is commonly used, otherwise there are the following dry agents:
drying agent capacity speed applications
calcium chloride, CaCl2 high medium used for hydrocarbons
calcium sulfate, CaSO4 (Drierite) low fast generally useful
magnesium sulfate, MgSO4 high fast not used for very acid-sensitive compounds
potassium carbonate, K2CO3 medium medium not for acidic compounds
sodium sulfate, Na2SO4 high slow generally useful
Tracy Ellis
Making pH Solutions To Make 200ml of each solution
To make a 200ml solution of pH1 to pH7 pH1 = .1 mol HCL 220ml (Base Solution) pH2 = 20 ml .1 mol HCL + 180ml distilled Water + 200ml = pH2 pH3 = 20 ml PH2 Solution + 180ml distilled Water + 200ml = pH3 pH4 = 20 ml PH3 Solution + 180ml distilled Water + 200ml = pH4 pH5 = 20 ml PH4 Solution + 180ml distilled Water + 200ml = pH5 pH6 = 20 ml PH5 Solution + 180ml distilled Water + 200ml = pH6 pH7 = Distilled water should have a pH of 7
To make a 200ml solution of pH14 to pH8 pH14 = 1.0 mol NaOH 220ml (Base Solution) pH13 = 20ml NaOH + 180ml Distilled Water = 200ml pH13 pH12 = 20ml PH13 + 180ml Distilled Water = 200ml pH12 pH11 = 20ml PH12 + 180ml Distilled Water = 200ml pH11 pH10 = 20ml PH11 + 180ml Distilled Water = 200ml pH10 pH9 = 20ml PH10 + 180ml Distilled Water = 200ml pH9 pH8 = 20ml PH9 + 180ml Distilled Water = 200ml pH8 pH7 = Distilled water should have a pH of 7
Correct Disposal of Agar Plates – Steve Garrett, Biotek
A pressure cooker is not manufactured and tested to industry standards recommended for sterilisation- it is a cooking instrument. To achieve the standards you require for sterilisation, you need a ‘steam steriliser’ or ‘autoclave’. Equipment used for sterilisation in industry is supposed to be tested and certified from time to time (just like your electrical items and fire extinguishers). As for decontaminating in a pressure cooker- not advisable (unless you have had it tested and certified). Pressure cookers are not designed for this purpose where there is a high load of organisms. Fine for media prep where there is an extremely low load of organisms (incidental to the preparation of media). Regardless of what equipment you use for the ‘decontamination’, the correct procedure is to remove all tape and plate closures, stack plates loosely and ensure that the bag that the plates are in is left fully open in the steriliser. There is an absolute necessity for the pressurised steam to penetrate everything for the process to be effective. I know from my conversations with some people that they do just the opposite- seal the plates, jam them in a bag and then seal the bag before putting it in the pressure cooker! Their reasoning is that they may have grown pathogenic organisms from environmental/personal swabs and don’t want them to escape. If ever there was an occasion where correct procedure should be followed, this is it- the steam (at correct temperature and pressure) must penetrate (for the correct period of time) for the process to be effective, otherwise they are defeating the purpose and then risking exposure of individuals to high concentrations of potentially pathogenic organisms! It has been recommended to me by the OGTR (Office of the Gene Technology Regulator) that schools do not use pressure cookers for decontamination as they are fearful that while genetic manipulations are allowed in schools, there is a real risk of environmental contamination if ‘assumed’ decontamination is undertaken using a pressure cooker... Their preferred method of decontamination is immersion in an industry standard decontaminant (eg hypochlorite), preferably overnight.
Page 12 - LabLINK November 2011
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The Floating Leaf Disk Assay for Investigating Photosynthesis Adapted for Yr 10 Students by Melissa Gould
This is an alternative method to explore photosynthesis other than using the oxygen-removing chemical, sodium dithionite or counting bubbles of oxygen produced by elodea. This method is suitable for further student-based enquiry.
The biology behind the procedure: Disks are cut from leaves and will float. When the oxygen is removed from the leaf by the application of a vacuum, the more dense sodium hydrogen carbonate will fill those spaces. The NaHCO3 is more dense that air and the leaf disk will sink. The HCO3 ion provides the carbon source for photosynthesis. As photosynthesis proceeds oxygen is released into the interior of the leaf which changes the buoyancy--causing the disks to rise. Since cellular respiration is taking place at the same time, consuming oxygen, the rate that the disks rise is an indirect measurement of the net rate of photosynthesis.
Materials: Sodium hydrogen carbonate, 0.2% solution (drop of dishwashing detergent added to wet the hydrophobic surface) Plastic syringe, 10mL Leaf material, spinach is suitable (if not fresh, stored in fridge to keep turgid so leaf cuts smoothly) Hole punch 50L beaker, 2 Light source, Alfoil, Stopwatch
Method: 1. Using the hole punch, cut at least 20 disks from the leaves, avoid major veins.
Place the leaf disks into the barrel of a 10mL syringe. Replace the plunger, taking care not to damage the disks.
2. Draw up approximately 3mL of the Sodium hydrogen carbonate/detergent solution into the syringe. Place the syringe upside down and depress the plunger to remove any trapped air.
3. Place thumb over the end of the syringe. Draw back the plunger to create a vacuum. Swirl the disks in the solution and hold the vacuum for 10 seconds.
4. Release the vacuum and check whether the disks are still floating. Repeat until most of the disks sink (at least 3 times).
5. Remove the disks from the syringe and divide between the 2 0 mL beakers. Add the sodium hydrogen carbonate solution to depth of 4cm, use same depth in both beaker. Remove any floating disks.
6. Cover one beaker with alfoil. Place the other beaker close to a light source or in the sun and start timing. Every minute, count and record the number of floating disks in each beaker. Swirl the beaker to dislodge any disks stuck to the glass.
7. Graph the results, time vs number of floating disks. The time when 50% of the disks are floating is referred to as the ET50. In extended investigations, the inverse (1/ET50) can be plotted against an independent variable such as light intensity to demonstrate the effect on photosynthesis.
Optional: Buffer Solutions, coloured filters, leaf material of different ages, variegated leaf material, clear Nail polish Notes:
Paper hole punch works fine when the leaf is turgid. Alternatively use stout plastic straws or cork borer.
Choice of the leaf material is perhaps the most critical aspect of this procedure. The leaf surface should be smooth and not too thick. Avoid plants with hairy leaves.
Avoid major veins.
If you have difficulty getting your disks to sink after about 3 evacuations, it is usually because there is not enough soap in the solution. Add a few more drops of soap.
For a control infiltrate leaf disks use a solution of only water with a drop of soap, without the bicarbonate. Place under the light source and start the timer. At the end of each minute, record the number of floating disks. Then swirl the disks to dislodge any that are stuck against the sides of the cups. Continue until all of the disks are floating.
Turn the light off at 14 minutes and the beaker with their floating disks were placed in the dark. Reference http://www.elbiology.com.labtools/Leafdisk.html
Page 14 - LabLINK November 2011
Making Hydrogen Debate
The following is the response from Carl Ahlers (Prof Bunsen) when questioned about the method of producing hydrogen described in his book and at his workshops. The RiskAssess software sets the production of 1mL of hydrogen as a maximum quantity, assuming it is the student carrying out the experiment rather than a teacher demonstration.
‘I know the RiskAssess software well and am actually a subscriber myself. I have been in contact with Dr Phillip Crisp of RiskAssess this morning to clarify the following:
It is important to realise that RiskAssess aims to provide teachers and lab technicians with safety guidelines for when they prepare practicals for students in the laboratory. It gives as guideline reasonable limits that would be 'safe' for students to handle hands-on in the average classroom set-up. It does not provide set limits. In this case a recommended volume of 1 ml per student for the preparation of hydrogen gas would be acceptable.
However, when an outside specialist or skilled chemistry teacher does demonstrations at a school and has extensive experience with a particular subject / preparation then the 1 ml guidance would of course not be applicable. The aim of RiskAssess is primarily to provide guidance on assessed risks that a science teacher may encounter in his / her classroom set-up. It never had an intention to limit outside presenters who have experience in presenting a particular subject.
I am of the opinion that if you are an experienced chemistry teacher and follow the safety guidance provided in my book and gain sufficient experience in this demonstration before you demonstrate this to a group, then you would be able to present it successfully and safely.
As a professional science presenter I may also mention that I have appropriate public liability insurance to 20 million dollars in place - the same insurance that a civil engineer would arrange as professional indemnity cover when designing a bridge.
May I wish you all the best in your endeavours to promote science as an exciting subject to your students.’ Carl Ahlers, Prof Bunsen Science, P O Box 7477, Geelong West, VIC 3218 Australia Ph: +61(0)3 5241 9756 Fax: +61(0)3 5244 4986 www.profbunsen.com.au [email protected]
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RiskAssess and Risk Assessments Advertisement
RiskAssess is a web-based tool to help Science Teachers and Lab Techs to carry out their risk assessments, in accordance with the law and in compliance with the DET Curriculum Activity Risk Management (CARM) Procedure. RiskAssess has been designed by Science Teachers and Lab Techs and is very easy to use. More than 520 schools around Australia use RiskAssess and over 130,000 risk assessments have been created on the system. RiskAssess provides helpful safety information on thousands of chemicals, items of equipment and living things; and is customized to the high school laboratory situation. Science staff can use this information, along with the information in MSDSs and their personal knowledge, to carry out their own risk assessments. RiskAssess provides an electronic template to assist users to conduct and record their risk assessments. RiskAssess also allows easy sharing, signing, printing and emailing of risk assessments. Lab Techs and Teachers carry out risk assessments on different activities. A teacher carries out a risk assessment on activities performed in the classroom; a LabTech carries out a risk assessment on the preparation of chemicals/equipment prior to class, and the cleanup after the class. Only the person actually carrying out an activity can do a risk assessment for that particular activity, since only that person can take into account all the factors, as is required by law. These factors include the facilities available, class size, emergency equipment, student behaviour and students with disabilities. The first step of carrying out a risk assessment is to assess the inherent risk level of an activity (risk level without any control measures) as low, medium, high or extreme. A risk matrix is used to assess the level of risk on the basis of the likelihood and consequences of adverse outcomes. If there are no significant risks, the inherent risk level is low and no additional control measures are needed. If the inherent risk level is medium or higher, sufficient control measures must be introduced to reduce the risk level to low. Any classroom experiment with a high or extreme inherent risk level should be checked and approved by the Principal or other authorized person. If sufficient control measures cannot be introduced to reduce the risk level to low, the experiment is too risky and should not be carried out. RiskAssess facilitates compliance with CARM requirements, by supplying the appropriate structure for conducting risk assessments. RiskAssess also includes a practical and equipment ordering system and an automatic lab scheduling system that Science staff find very useful. The scheduling system provides a calendar of future practicals and allows Lab Techs to mark these off when they have been prepared. In 2012, we plan to introduce the Globally Harmonised System of Classification and Labelling of Chemicals to the chemical database. If you have any questions or if we can be of any assistance, please contact us at [email protected] or phone Dr Phillip Crisp on 02 9415 8677. The cost of subscribing to RiskAssess is $160 (plus GST) per year, covers all science staff on one campus, and includes all upgrades during the year. If you are interested in trying out RiskAssess for 2 weeks for free, please email your school name to [email protected]. The RiskAssess Team www.riskassess.com.au
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Miracle berry's sweet secret Dr Karl Kruszelnicki
Dr Karl Kruszelnicki’s Great Moments in Science http://www.abc.net.au/science/drkarl/greatmomentsinscience/ If you could miraculously make bitter food turn sweet, would you do it? Dr Karl reveals the secret to the amazing taste trick of miracle fruit. After eating a miracle berry from tropical West Africa then eating an acidic or bitter substance all you taste is sweetness; beer tastes like sweet juice, lemon tastes like sweet orange. The active ingredient in miracle fruit is a mid-size chemical called miraculin. It has a molecular weight that is about five-times heavier than insulin, or 1400 times heavier than water. Each taste bud on your tongue holds about 50–100 taste receptor cells. Each of these taste receptor cells will respond to only one of the five basic tastes: sweet, salt, sour, bitter and umami. When this chemical lands on your tongue. Your tongue has the sense of taste because it's covered with a few thousand taste buds. The tiny receptors in the taste buds are hollow and if a chemical comes along that fits neatly into the receptor, like a key in a lock, the taste receptor cells do something – tell the brain that it has tasted one of the five tastes. The active ingredient, miraculin, is a pretty bad fit into the sweet receptor under normal conditions, tghe lock will not work, but in acidic conditions it fits more precisely and makes the sweet receptors extra sensitive and the brain receives the message from the sweet receptor that there is a lot of sweetness on your tongue even though you may be eating a very sour lemon. The miraculin chemical will hang in there inside your sweet receptors on your tongue for over an hour before it leaves. Scientists are using genetic engineering to modify other plants, such as fruits or vegetables, to grow the active ingredient, miraculin. So this natural product could be used, say, for diabetics to satisfy their sweet tooth without the extra calories or kilojoules that sweetness normally brings. The taste buds may be fooled but with an excess of acidic foods in the stomach, a tummy ache is a distinct possibility.
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Snake Display
When Eliane Costa volunteered her method of preserving snake skins, we decided that those dried up skins our resident student herpetologist had left with us could be turned into a dramatic display for our newly refurbished display cases. The skins were carefully laid out on pieces of foam, sprayed with water to soften them so it was possible to tease them out using a blunt spatula. The skins were extremely fragile after sitting in plastic bags for over a year. As the skins were stretched out, pins were placed to hold them flat and extended. They were then allowed to dry before laminating them. Our
student expert had supplied the skins complete with scientific names, common names, family and deathliness rating. Armed with this information we developed posters that included photos of the snake in all its glory and descriptions of characteristics and habitat. One of the skins was from a large woma python, with sections still intact. By stapling overhead transparencies into tubes and
gently feeding them inside the skin, the skin could be displayed as it would have been on the snake. The liquid in which our old snake specimens had been preserved was refreshed with 70% ethanol + dash of glycerol and relabelled. These were added to the display. Jill Clothier & Jackie Reddaway, Caboolture SHS
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Copper Plating Christmas Ornament - Metal Star Ornament
http://chemistry.about.com/od/demonstrationsexperiments/a/copperornament.htm An alternative to a holiday cooking chemistry project is to use your command of redox chemistry to make a keepsake ornament. Can you think of a better way to remember how much fun you had in chem class? Materials
metal for the ornament - you could use squares of galvanized sheet metal that have a hole drilled at the top for hanging the ornament, or craft metal from a hobby shop, or galvanized wire. Masking tape copper (II) nitrate solution (~0.1M) pencil, utility knife , steel wool, tin snips (optional)
Procedure
1. If desired, cut or form your metal into a snowflake or star or other holiday shape. Wire can be wrapped around a sphere to make a glittering ball or you can bend it to conform to a traced shape (like a star or angel).
2. Once you have a shape you like, use sandpaper or steel wool to smooth any rough edges. If you want part of the ornament silver (zinc-coloured) and part copper, cover all areas you want to remain silver with masking tape.
3. You can use a utility knife to etch a design into the masking tape or can scratch the tape away with an awl or any sharpened object. This is nice if you have a rigid piece of metal and simply want to decorate it with a shiny copper design.
4. Dip the ornament in the copper nitrate solution until the uncovered areas are coated with the metal. Alternatively, you can use a cotton swab dipped in the solution to paint a design onto the metal.
5. Rinse your ornament with water, remove any masking tape, and allow your decoration to dry.
Tips & Ideas 1. To 'galvanize' a metal is to coat it with a layer of zinc metal. Zinc resists corrosion, so in this project, the
galvanized metal of the untreated sections remains shiny. However, you can plate copper onto other metals, so if you have a different metal ornament you can make and wish to coat, feel free to experiment with it.
2. If the metal is dirty or you wish to remove its coating, you can dip it in dilute hydrochloric acid (HCl) until the bubbling stops, rinse with water, then treat with the copper nitrate solution.
Making Coloured Fire
The following is an extension of flame tests using pine cones or sawdust that have been soaked in solutions of metal salts, allowed to dry and then ignited. Naturally all risks are to be assessed and controls instigated to render the risk as LOW.
Pour water into a container large enough to hold the pine cones or sawdust.
Stir in the metal salt until no more will dissolve (if using sawdust, some liquid glue can be added to cause the sawdust to form clumps.
Add the pine cones / sawdust and mix to coat evenly.
Let the material soak for several hours or overnight.
Remove from the solution and spread out to dry. By spreading the sawdust onto paper, the paper will also burn with the characteristic colour.
Colour Chemical Colour Chemical
Carmine Lithium chloride Yellow/green Borax
Red Strontium chloride Green Copper sulphate
Orange Calcium chloride Blue Copper chloride
Yellow Sodium Violet 3 parts Potassium sulphate:1 part Potassium nitrate
Purple Potassium chloride White Magnesium sulphate
Reference: http://chemistry.about.com/cs/howtos/a/aa052703a.html
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Silver Crystals on a Copper Tree
( Anne Marie Helmenstine, Ph.D., About.com Guide) In this simple chemistry demonstration or crystal project you'll grow a silver crystal tree. This is a variation of the classic method of growing silver crystals on a copper wire or bead of mercury. Silver Crystal Tree Materials
sheet of copper that has been cut into a tree shape or a tree made from copper wire 0.1 M silver nitrate solution
Grow a Silver Crystal Tree All you need to do is place the copper tree into the silver nitrate solution. Silver will be reduced on the copper, forming silver crystals. Crystals begin forming immediately and should be visible within an hour. You can allow the silver crystal tree to sit in an undisturbed location for a day or two for peak crystal growth. How It Works A displacement reaction is responsible for crystal formation: 2 Ag+ + Cu → Cu2+ + 2 Ag When you are finished growing the silver crystals, you can remove the tree from the solution and use it as a decoration.
How To Grow a Borax Crystal Snowflake
( Anne Marie Helmenstine, Ph.D., About.com Guide) Grow a borax crystal snowflake, colour it blue if you like, and enjoy the sparkle all year long! A video tutorial showing how to grow borax crystal snowflakes is also available. What You Need
string wide mouth jar (pint) white pipe cleaners borax (see tips) pencil boiling water blue food coloring (opt.) scissors
Here's How:
The first step of making borax crystal snowflakes is to make the snowflake shape. Cut a pipe cleaner into three equal sections.
Twist the sections together at their centres to form a six-sided snowflake shape. Don't worry if an end isn't even, just trim to get the desired shape. The snowflake should fit inside the jar.
Tie the string to the end of one of the snowflake arms. Tie the other end of the string to the pencil. You want the length to be such that the pencil hangs the snowflake into the jar.
Fill the wide-mouth pint jar with boiling water.
Add borax one tablespoon at a time to the boiling water, stirring to dissolve after each addition. The amount used is 3 tablespoons borax per cup of water. It is okay if some undissolved borax settles to the bottom of the jar.
If desired, you may tint the mixture with food colour.
Hang the pipe cleaner snowflake into the jar so that the pencil rests on top of the jar and the snowflake is completely covered with liquid and hangs freely (not touching the bottom of the jar).
Allow the jar to sit in an undisturbed location overnight.
Look at the pretty crystals!!! You can hang your snowflake as a decoration or in a window to catch the sunlight.
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Science fiction or the future of Bio-nanotechnology
Bacteria are remarkable in that they are capable of switching between aerobic and anaerobic respiration using a variety of compounds such as metals. When oxygen is scarce, novel microorganisms known as Geobacter bacteria can use projections called "microbial nanowires" to transfer electrons onto terminal electron acceptors such as iron oxides in the soil.
The nanowires are only 3-5 nanometres in width (20,000 times finer than human hair), but so long that the bacteria are akin to breathing through a 10km long snorkel.
These nanowires function like a real wire, with conductivity comparable to that found in synthetic conducting polymers used in the electronics industry. Manufacturing nanowires from traditional materials such as metals, silica or carbon is difficult and expensive. However, it is easy to grow billions of Geobacter cells in the laboratory and harvest their microbial nanowires. Imagine using mass produced biological nanowires in miniaturised electronic devices or microbially based fuel cells.
The Night to Make Crystals John F. Hansen, reprinted from “The Chemical Bond”, St. Louis Section ACS, December 1978
‘Twas the night to make crystals, and all through the hood, Compounds were reacting; I’d hoped that they would. The hood door I’d closed with the greatest of care, To keep noxious vapours from fouling the air. The reflux condenser was hooked to the tap, And the high vacuum pump had a freshly filled trap. I patiently waited to finish my task, While boiling chips merrily danced in the flask. Then from the pump there arose such a clatter That I sprang from my chair to see what was the matter. Away to the fume hood! Up with the door! And half of my product foamed out on the floor. Then what to my watering eyes should appear, But a viscous black oil which had once been so clear. I turned the pump off in a terrible rush, And the oil that sucked back filled the line up with mush. The ether boiled out of the flask with a splash, And hitting the mantle went off with a flash. My nose turned quite ruddy, my eyebrows went bare, The blast had singed off nearly half of my hair. I shut the hood door with a violent wrench, As acid ate holes in the floor and the bench. I flushed it with water and to my dismay, Found sodium hydride had spilled in the fray. And then e’er the fire got way out of hand, I managed to quench it with buckets of sand. With aqueous base I diluted the crud, Then shovelled up seven big buckets of mud. I extracted the slurry again and again With ether and then with dichloromethane. Chromatographic techniques were applied Several times ‘til the product had been purified. I finally viewed with a satisfied smile, One half a gram in a shiny new vial. I mailed the yield report to my boss, Ninety percent (allowing for loss). “Good work”, said the boss in the answering mail, “Use same conditions on preparative scale.”
