STEM%Outreach%at%CU%Denver%Activity'Description''

DNA%in%a%Bottle%Contributed'by:'Community'STEM'Clubs'Program'

'Purpose:'to'introduce'students'to'the'basics'of'DNA''Background%'

Deoxyribonucleic'Acid'(DNA)'carries'the'genetic'information'vital'to'the'development'and'functionality'of'living'organisms.'These'biological'instructions'are'encoded'into'DNA’s'chemical'structure'as'nucleotide'chains.'In'extracting'their'DNA,'students'can'see'what'determines'their'blood'type,'their'hair'color,'and'even'their'predisposition'to'certain'diseases.'

'Overview%%

This'activity'consists'of'mainly'two'parts:'instruction'and'a'lab'experiment.'Students'will'be'introduced'to'basics'of'the'human'genome'and'DNA.'

'Materials%%

500'mL'per'10'students'–'drinking'water'1'Tbsp'per'10'students'–'salt'100'mL'per'10'students'–'isopropyl'alcohol'2'per'10'students'–'large'cup'or'beaker'(at'least'500'mL)'1'per'student'–'clear'(plastic)'cup'1'per'student'–'coffee'stirrer'or'hot'straw'1'per'student'–'take'home'size'plastic'bottle'(think'party'bubble'container)'petri'dish'or'extra'cup'dish'soap'food'coloring'superglue'

'DNA%Structure%%

Our'presentation'begins'by'building'up'to'a'complete'DNA'structure.'Starting'with'the'four'nitrogen'bases'(adenine,'cytosine,'guanine,'and'thymine)'we'add'the'ribose'and'phosphate'groups'while'adding'comments'and'discussion'about'each.'We'then'talk'about'how'the'nitrogen'bases'pair'and'are'bonded'together'to'form'a'DNA'strand,'and'how'DNA'packs'into'chromosomes'that'are'visible'through'a'microscope.'With'a'broad'picture'in'place,'we'contextualize'the'relative'size'growing'through'nucleotides,'genes,'DNA,'and'chromosomes,'which'are'found'primarily'within'the'nucleus'of'cells.''A'message'to'keep'in'mind'throughout'is'how'we'start'with'something'so'small'and'how'we'expect'to'be'able'to'see'the'DNA'once'it'is'extracted.'

STEM%Outreach%at%CU%Denver%Activity'Description'''DNA%Extraction''

The'DNA'extraction'lab'proceeds'as'follows:'1. Mix'500mL'of'drinking'water'with'one'(1)'Tbsp'salt'2. Stir'mixture'until'salt'is'dissolved'3. Transfer'three'(3)'Tbsp'of'salt'water'mixture'into'a'clear'cup'4. Gargle'the'cup'of'salt'water'for'one'(1)'minute'5. Spit'the'salt'water'back'into'the'cup'[cheek'cells'are'suspended'in'the'

salt'water]'6. Put'one'(1)'drop'of'soap'into'cup/petri'dish.''7. Rub'a'stirrer'end'in'the'soap'and'use'that'end'to'slowly'stir'in'a'single'

direction'(avoid'bubbles)'the'salt'water'mixture'with'cheek'cells'[soap'releases'DNA'by'breaking'down'cell'membranes]'

8. In'a'separate'cup,'mix'100mL'of'isopropyl'alcohol'and'three'(3)'drops'of'food'coloring.'

9. Tilt'the'salt]water'cup'and'gently'pour'in'the'colored'isopropyl'alcohol'until'it'forms'a'2cm'layer'on'top.'

10. Wait'approximately'2.5'minutes'for'white'clumps'and'strings'to'start'forming'[that’s'the'DNA]'

11. Fill'a'small'“take'home”'bottle'with'isopropyl'alcohol'12. Stir/twirl'the'stirrer'in'one'direction'to'wind'DNA'strands'around'the'

stirrer'(avoid'mixing'isopropyl'alcohol'and'water)'13. Shake'the'DNA'on'the'stirrer'into'the'take'home'bottle.'14. Top'off'the'bottle'with'isopropyl'alcohol'and'superglue'the'cap'shut'

'Modifications%and%Extensions%%

The'instruction'portion'can'be'tailored'to'many'student'levels.'From'basic'genetic'inheritance'in'the'work'of'Gregor'Mendel'to'more'complex'discussions'on'gene'expression'and'regulation,'there'is'a'genetic'discussion'accessible'to'any'level.'In'particular,'there'are'common'misconceptions'about'genetics'and'DNA'that'can'be'addressed.''Rather'than'cheek'cells,'DNA'can'be'extracted'from'practically'any'living'organism.'In'the'classroom,'strawberry,'broccoli,'and'split'pea'DNA'can'be'extracted'with'the'addition'of'a'blender,'strainer,'and'meat'tenderizer.''The'details'of'how'the'ethanol'precipitation'relies'on'some'basic'chemistry'and'could'offer'higher]level'students'with'an'interesting'topic'of'conversation.''The'following'trivia'facts'about'DNA'can'make'a'fun'game.'- Human'beings'share'a'common'99%'of'DNA'code'

STEM%Outreach%at%CU%Denver%Activity'Description''

- The'DNA'from'a'single'human'put'end'to'end'could'travel'to'the'sun'and'back'over'600'times'(moon'and'back'6000'times)'

- Typing'at'60'words'per'minute,'it'would'take'~50'years'to'type'the'human'genome'

- Errors'are'caused'by'alterations'to'a'human’s'DNA'about'1000'times'a'day'

- DNA'was'discovered'in'1869'(by'Fredrich'Miescher)'but'not'understood'as'genetic'material'until'1943'

- Mature'red'blood'cells'are'the'only'human'cells'without'DNA;'the'nucleus'is'squeezed'out'to'make'room'for'carrying'hemoglobin'

- Humans'have'46'chromosomes'- There'are'4'DNA'bases,'4'RNA'bases,'and'20'amino'acids.'- There'are'about'3'billion'bases'in'our'genome'- We'have'about'20,000]25,000'genes'- Only'1.5%'of'the'human'genome'is'made'of'genes'- A'complete'genome'takes'about'3'gigabytes'of'memory'to'store'- DNA'in'one'cell'can'stretch'up'to'6'feet'long'(at'50'trillinths'of'an'inch'

wide)'- Humans'have'98%'of'DNA'in'common'with'a'chimpanzee,'85%'with'a'

zebrafish,'60%'with'a'banana,'57%'with'a'cabbage,'36%'with'a'fruit'fly,'21%'with'a'roundworm,'15%'with'rice,'and'2%'with'e.'coli'

%Some%References''http://ghr.nlm.nih.gov/handbook/basics/dna''http://www.genome.gov/25520880''http://www.genome.gov/10001772''http://www.nature.com/scitable/topic/genetics]5''http://www.hhmi.org/biointeractive/dna]packaging''http://knowgenetics.org/common_misconceptions/''http://learn.genetics.utah.edu/content/labs/extraction/howto/''http://bitesizebio.com/253/the]basics]how]ethanol]precipitation]of]dna]and]rna]works/''Attachments''Basic'slides'for'instruction'on'DNA'structure'

Compiled'by'Axel'Brandt'as'part'of'the'CU'Denver'Community'STEM'Clubs'program.'Special'thanks'to'

What%is%DNA?%

DNA%Structure%

1.  Nitrogenous%Base%

DNA%Structure%

1.  Nitrogenous%Base%2.  Ribose%Sugar%

DNA%Structure%

1.  Nitrogenous%Base%2.  Ribose%Sugar%3.  Phosphate%Group%

DNA%Structure%

DNA%Structure%

DNA%packaging%

h?p://www.hhmi.org/biointeracDve/dnaGpackaging%

h?p://learn.geneDcs.utah.edu/content/molecules/dnathings/%

Things%You%May%Not%Know%About%

DNA%

%Extract%your%DNA%from%cheek%cells%