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BY ALL STAFF MEMBERS

OF MEDICAL BIOCHEMISTRY DEPARTMENT

LABORATORY INSTRUMENTS AND APPARATUSES

By the end of this topic, the student will be able to: Identify and categorize the different instruments and apparatuses with their parts and uses in practice.

Glasswares:• Beakers• Erlenmeyer flasks• Test tubes

Heating:• Tripod stand• Bunsen Burner

Experimental Apparatus:• spectrophotometers

Holding and Grabbing:• Test tube Rack• Spatula

Filtering:• Filter Paper• Funnel

:Observing• Petri Dish• Watch Glass

Outlines

Glass wares

*Instruments for Liquid Volume Measurements

Liquid Volume Measurements

Instruments used for volume measurement depends on the accuracy and volumes needed. The smaller the

diameter of the instrument the more accurate it would be e.g. pipettes.

Pipettes

A pipette measures and delivers exact volumes of liquids.

Glass graduated pipettes

used to transfer small-volumes of liquids e.g.

(1ml-10ml)

Automatic pipetteMost accurate of all, used to transfer micro- volumes of liquids e.g. (1l-1000l)

Automatic pipette tips

Graduated CylindersA graduated cylinder is used to measure different volumes of liquids.

Volumetric flasks

A volumetric flask is used for the preparation of solutions with different concentrations and

volumes.

*Instruments For Transfer, Mixing Boiling And storage

of Chemicals

Test tubes

-Used for performing chemical experiments and reactions in lab. e.g. -Holding liquid samples for heating, dissolution, centrifugation, and other

Reagents and Chemicals Bottles

Used for: Storage of different chemicals, reagents, and even strong corrosives. So, they should always carry an informative label.

Graduated Beakers

A beaker holds solids or liquids that will not release gases when reacted or are unlikely to splatter if stirred or heated.

precise; expensive

Range:

Glassware – Precision and Cost

beaker vs. volumetric flask

When filled to 1000 mL line, how much liquid is present?

beaker 5% of 1000 mL = 50 mL

volumetric flask1000 mL + 0.30 mL

950 mL – 1050 mL 999.70 mL– 1000.30 mL

imprecise; cheap

Range:

Erlenmeyer flasks (conical flasks) hold solids or liquids that may release gases during a reaction or that are likely to splatter if stirred or heated.

Erlenmeyer Flask (conical flask)

Rounded Flask (Florence Flask)

Round (Florence) flask is rarely used; it is used for the mixing of chemicals. Narrow neck prevents splash exposure on heating or stirring.

Heating

These objects are all used in the process of heating, but each one has a different function.

Bunsen Burner

Wire gauzeTripod stand Boiling Tube

Bunsen burners are used for the heating of nonvolatile liquids and solids.

Bunsen Flame

Crucible

Crucibles are used for heating certain solids, particularly metals, to very high temperatures.

Evaporating Dish

The evaporating dish is made of porcelain or ceramic to withstand heat; as it’s used for the heating of stable solid compounds and elements.

Glass Stir Rod

A glass rod is used to manually stir solutions. It can also be used to transfer a single drop of a solution.

* Instruments used For handling

of Chemicals

It is inserted into the end of the glass pipette to help the delivery of liquid without suction by mouth.

Pipette pump

It resembles small paddles or teaspoons. It resists corrosions. It is

used to handle solid powdered chemicals.

Spatula

Plastic Pasteur

transfer Pipette

Droppers & Plastic transfer

pipette

They are used to transfer small amounts or drops of liquid solutions.

Test tube RackTest tube racks are for holding and organizing

test tubes on the laboratory counter. Plastic racks may melt in contact with very hot

test tubes.

Test Tube Holder

A test tube holder is useful for holding a test tube which is too hot to handle.

Rubber Stoppers

Rubber stoppers are used to close containers to avoid spillage, evaporation and /or contamination. Containers should never be heated when there is a stopper in place.

Well Plates

Well plates are used when we want to

perform many small scale reactions at one

time.

Washing Bottle

A wash bottle has a spout that delivers a wash solution to a

specific area. Distilled water is the only liquid that should be

used in a wash bottle.

Test Tube Brushes

Test tube brushes are used to clean test tubes and graduated cylinders.

Forcing a large brush into a small test tube will often break the tube.

Forceps

Forceps (or tweezers) are used to pick up small objects.

Weighing Tray

Weighing boats are used to weigh solids that will be transferred to another vessel.

Petri dishUsed for culture studies and for preparing

agar plates.

Observing

Watch Glass

Used as a surface to observe powder consistency . It may be used as a beaker cover or as a weighing tray.

*Instruments used For Filtration

FunnelsA funnel is used to aid in the transfer of liquid from one vessel to

another.

Filter papersOuter rough surface

Inner smooth surface

Activity: Label the given illustrative diagram showing the filtration of magnesium carbonate.

1

2

3

*Instruments Used For Detecting pH And Recording of Temperature And

Specific Gravity

Litmus Paper

Red litmus paper is used to identify bases.

Blue litmus paper is used to identify acids.

ThermometerCalibration marks along it, allow the temperature to be read by the length of mercury within it. It is used usually to measure the temperature of water bath in

lab.

Urinometer (Hydrometer)

Used to measure the specific gravity of a

liquid e.g. urine

*Apparatuses and their parts Used in Lab

Lab water bath

Water Bath provides precise temperature for lab reactions control and is available with an analog or digital operating system

Balance

Used to weigh chemicals

Centrifuge

Spins liquid samples at different high

speeds to sediment different fractions.

Gel electrophoresis Apparatus

Tank

combs

Glass plates

separators

Gel

Tank cover

Used to separate macromolecules as DNA , RNA and Protein

Comb of gel-electrophoresis

Forms wells in the gel which are needed to load samples in them.

paper electrophoresis Apparatus

Spectrophotometer

Used to measure the absorbance (O.D) of different substances in biological fluid; using it to calculate the

corresponding concentrations.

Cuvette

pH meterBulb of pH

meter

Used to measure the pH of a solution.

Measurement by glass wares

~ ~ ~ ~ ~

water ingrad. cyl.

mercury ingrad. cyl.

There are some materials where the curve goes up. Still, you read the

horizontal center of the meniscus

(top of the meniscus).

In some plastic cylinders water has a flat surface. In that case top or bottom doesn't matter, but we can still say use

the center rather than the edges.

A characteristic of liquids in glass containers is that they curve at the edges. This curvature is called the meniscus. You measure

the level at the horizontal center or inside part of the meniscus.

The Meniscus

Glass Graduated Cylinder

Reading the Volume from a 100-mL Graduated Cylinder

IMAGE. 100-mL graduated cylinder.Step 1: Determine the scale increment:

How? Answer:In shown Fig, the large graduations

are(10,20,30,40,50,60ml --- etc) between 60 mL and 50 mL = 10 mL. Next, ten small

intervals between the large labeled graduations. Therefore, the scale increment is 10 mL/10 graduations = 1 mL/graduation.

Step 2: Use the labeled graduations and the scale increment to measure.

How? Answer The volume is greater than 50 mL, Next, use the scale increment. There are two graduation marks below the meniscus, and each graduation represents 1 mL, so the certain digits of the reading are 52 mL

Identify each volume to two decimal places(values tell you how much you have expelled)

4.50 mL 4.8mL 5.00 mL

Activity: Reading a pipette

Dr/ Amal Mansour