!!

What!your!DNA!says!about!you!!

GEMS%

October%3,%2015%

You%can%do%this%experiment%at%

home!%%%

All%you%have%to%do%is%substitute%

• The%8%%sodium%chloride%solution%for%a%drop%or%two%of%detergent%

• SDS%solution%and%EDTA%solution%together%can%be%switched%out%for%a%

pinch%of%meat%tenderizer%(pineapple%juice%works%as%well!).%%

%

You%could%also%try%different%foods%as%well%to%compare%DNA,%these%foods%

work%really%well:%Banana,%strawberries,%kiwi%fruit,%onion,%liver%and%beef%

thymus.%You%will%need%to%squish%up%the%food%and%then%drain%all%the%liquid%out%

and%use%the%liquid%instead%of%cheek%cell%water.%%%

%

What%happened?%%DNA%is%usually%very%small,%but%if%you%get%a%large%amount%of%it%together%then%

it’s%natural%clumping%nature%will%make%it%into%a%mass%big%enough%to%see!%The%

first%step%was%to%collect%the%cells;%our%cells%come%off%rather%easily;%every%time%

we%touch%something%our%skin%cells%fall%off.%So%the%swishing%of%the%liquid%was%

enough%to%break%off%the%cells%from%your%cheek.%%

%

The%detergent%was%necessary%because%of%the%nature%of%cells,%the%outer%

membrane%of%cells%are%made%out%of%lipids%which%are%fatty%molecules%that%

repel%water.%Detergents%are%used%for%cleaning%because%they%are%able%break%

apart%these%fatty%molecules%from%each%other.%This%released%the%inside%of%the%

cell,%containing%the%DNA,%for%us.%%

%

DNA%is%tightly%wound%in%the%nucleus%of%cells%so%that%all%of%the%DNA%that%you%

have%will%fit%into%such%a%small%space.%One%strand%of%DNA%stretched%out%would%

be%up%to%2%or%3%meters%long.%Since%we%want%to%see%the%DNA%we%want%it%to%be%

as%stretched%out%as%possible.%DNA%is%held%together%by%proteins%to%make%sure%

it%doesn’t%unravel,%enzymes%break%down%these%proteins%allowing%the%DNA%to%

unwind.%%

%

The%alcohol%is%used%because%DNA%is%not%soluble%in%it.%That%way%the%DNA%

precipitates%(clumps%together)%out%into%the%alcohol%layer%while%leaving%

behind%the%lipids%and%proteins.%

!

Lorem!&!Ipsum! [Insert!Date!\!Issue]!

7%2%

DNA%BRACELET%

TABLE%OF%CONTENTS%

Page%3%

How%DNA%makes%us%unique%

%

Page%4`5%

Extracting%DNA%

%

Page%6%

DNA%Structure%%

%

Page%7%

DNA%Bracelet%

%

Page%8%

At%Home%Experiment%

%

%

THIS%LAB%NOTEBOOK%BELONGS%TO:%

%

%

________________________________________________%

Now%that%you%know%how%DNA%is%organized%you%can%make%your%own%

DNA%structure%bracelet.%This%bracelet%is%made%out%of%two%strings%

with%complementary%base%pairing.%On%the%table%are%some%different%

DNA%sequences%for%various%organisms.%This%DNA%sequence%is%one%

string%of%your%bracelet,%you%will%have%to%come%up%with%the%

complementary%base%pair%in%order%to%make%the%second%one!%

%

Hint:%You%can%write%down%your%sequence%below%and%use%it%to%figure%

out%the%complementary%base%pair%in%your%booklet.%Then%you%can%

follow%it%to%make%the%bracelet.%

%

%

Sequence:%

%

Base%pairs:%

%

%

Bracelet:%

A`%Green%

T`%Red%

G`%Yellow%

C`%Blue%

%

Tie%two%strings%together.%String%the%given%DNA%sequence%of%your%

desired%organism%onto%one%string.%Now%you%can%string%your%

complementary%base%pairs%onto%the%other%string.%When%done,%tie%a%

knot%at%the%other%end%of%the%string.%You%can%then%tie%the%two%ends%

together%to%make%a%bracelet!%

!!

!!

!

Lorem!&!Ipsum! [Insert!Date!\!Issue]!

3%6%

HOW%DNA%MAKES%US%

UNIQUE%

DNA%STRUCTURE%

DNA%is%made%out%of%nucleotides;%which%contain%a%sugar,%a%phosphate,%

and%a%base%that%makes%up%the%DNA%code.%Adenine%(A),%Cytosine%(C),%

Guanine%(G),%and%Thymine%(T)%are%the%four%bases%used%and%they%follow%the%

rules%of%complementary%base%pairing,%rules%that%govern%how%DNA%is%

created.%Adenine%in%one%DNA%strand%must%connect%to%Guanine%in%the%

second%strand.%Similarly,%Cytosine%connects%to%Thymine.%

%

%%

Try%this%practice%sequence:%

%

A%G%C%T%T%A%G%C%T%A%A%T%G%C%CC%T%G%G%T%A%C%

%%

%

Now$you$can$create$your$own$DNA$sequence$bracelet!$

%

%

%

%

%

Our%sequence%of%DNA%says%a%lot%about%us.%Codes%in%our%DNA%

make%up%our%genes;%these%are%regions%on%our%DNA%that%

determine%what%our%phenotypic%traits%will%be.%Phenotypic%

traits%are%things%that%we%can%see,%such%as%someone’s%hair%or%

eye%color.%Phenotypic%traits%are%inherited,%that%means%that%

your%genes%are%passed%to%you%by%your%mother%and%father.%%

%

Are%you%a%taster%or%non`taster%for%PTC?%

%

%

Are%you%a%taster%or%non`taster%for%Thiourea?%

%

%

Write%down%what%you%tasted%for%Sodium%Benzoate.%Did%you%

taste%sweet,%sour,%salty,%bitter%or%were%you%a%non`taster?%

!%

The%ability%to%taste%these%chemicals%are%based%on%your%

genes!!%%

!%

!

Lorem!&!Ipsum! [Insert!Date!\!Issue]!

!!!!!!!!!!!!!

5%4%

4. %Add%1%mL%(20%drops)%of%10%%SDS%solution%and%1%mL%of%0.1%

EDTA%solution%to%your%test%tube.%%

5. Put%cap%back%on%and%let%sit%for%5%minutes%

6. Tilt%your%test%tube%to%a%45%degree%angle.%VERY%gently%pour%~5%

mL%(~100%drops)%95%%ethyl%alcohol%down%the%side%of%the%tube%

so%it%creates%a%layer%on%top.%%

Why$do$you$think$we’re$adding$alcohol?$$$$$$$$

7. Return%to%upright%position%and%let%sit%for%1%minute%

8. You%should%see%DNA%floating%in%the%alcohol%layer.%%

%

What$appearance$does$the$DNA$have?$Color?%%

%

%

%

%

%

9. Fill%an%Eppendorf%tube%with%1%mL%of%ethyl%alcohol.%You%can%use%

a%wooden%skewer%to%wrap%the%DNA%and%lift%it%out%of%the%test%

tube%and%into%your%Eppendorf%tube.%

10. You%can%take%your%tube%of%DNA%and%attach%it%to%a%necklace%

string%by%closing%the%lid%of%the%tube%over%the%string.%%

%

%

%

%

%

A%single%strand%of%DNA%is%tiny;%only%2%nanometers%across!%

However,%much%of%DNA%is%coiled%inside%of%the%nucleus%in%order%to%

fit%it%all%inside%of%a%small%cell.%Using%a%few%ingredients%(which%you%

can%probably%find%in%your%kitchen)%you%can%extract%the%DNA%from%a%

sample%of%your%cheek%cells%that%will%be%large%enough%for%you%to%

see.%%

%

Materials:%

%

• Cup of water • 8% sodium chloride solution • 10% SDS solution • 0.1 EDTA solution • 95% Ethyl Alcohol • Test Tube • Eppendorf tube

%

Procedure:%%

%

1. Vigorously%swish%water%in%your%cup%around%your%mouth%for%

at%least%1`2%mins.%Make%sure%to%do%it%this%amount%of%time`

the%longer%you%swish,%the%more%cells%you%will%get.%%

2. Spit%it%back%into%your%cup.%Take%a%test%tube%and%put%1%mL%

(20%drops)%of%8%%sodium%chloride%solution%into%it%

3. Pour%your%mouth%water%into%the%test%tube%until%it%is%half%

full.%Put%the%cap%on%and%gently%mix%by%inverting%the%tube%a%

few%times.%Not%too%hard,%we%don’t%want%to%create%bubbles.%

The$NaCl$solution$causes$the$cell$wall$of$the$cheek$cells$to$break$apart.$Why$do$you$think$this$is$necessary$to$isolate$the$DNA?$$$$$

EXTRACTING%DNA%