Justfollowthese3easysteps:

Detergent

eNzymes(meattenderizer)

Alcohol

It"sthatsimple?Tellmemore!

First,youneedtofindsomethingthatcontainsDNA.SinceDNAistheblueprintforlife,everythinglivingcontainsDNA.

Forthisexperiment,weliketousegreensplitpeas.

ButtherearelotsofotherDNAsourcestoo,suchas:

• Spinach
• Chickenliver
• Onions
• Broccoli

Here"sthefunpart.Putinablender:

• YourDNAsource(about100mlor1/2cupofsplitpeas)
• Alargepinchoftablesalt(lessthan1mlor1/8teaspoon)
• TwiceasmuchcoldwaterastheDNAsource(about200mlor1cup)

Blendonhighfor15seconds.

Theblenderseparatesthepeacellsfromeachother,soyounowhaveareallythinpea-cellsoup.Becausethisstepisprettymessy,certainsourcesofDNAshouldnotbeused,suchas:

• Yourfamilypet,Fidothedog
• Yourlittlesister"sbigtoe
• Bugsyoucaughtintheyard

Andnow,those3easysteps:

1.Pouryourthinpea-cellsoupthroughastrainerintoanothercontainer(likeameasuringcup).

Howmuchpeasoupdoyouhave?Addabout1/6ofthatamountofliquidDetergent(about30mlor2tablespoons)andswirltomix.Letthemixturesitfor5-10minutes.

Pourthemixtureintotesttubesorothersmallglasscontainers,eachabout1/3full.

Tryoneofthesedetergentsorwhateveryouhaveonhand.

WhyamIaddingdetergent?

2.Addapinchofenzymestoeachtesttubeandstirgently.Becareful!Ifyoustirtoohard,you"llbreakuptheDNA,makingithardertosee.

Usemeattenderizerforenzymes.Ifyoucan"tfindtenderizer,tryusingpineapplejuiceorcontactlenscleaningsolution.

Whatisanenzyme?

3.Tiltyourtesttubeandslowlypourrubbingalcohol(70-95%isopropylorethylalcohol)intothetubedownthesidesothatitformsalayerontopofthepeamixture.Pouruntilyouhaveaboutthesameamountofalcoholinthetubeaspeamixture.

DNAwillriseintothealcohollayerfromthepealayer.YoucanuseawoodenstickorotherhooktodrawtheDNAintothealcohol.

Whatisthatstringystuff?

Alcoholislessdensethanwater,soitfloatsontop.Sincetwoseparatelayersareformed,allofthegreaseandtheproteinthatwebrokeupinthefirsttwostepsandtheDNAhavetodecide:"Hmmm...whichlayershouldIgoto?"

Thisissortoflikelookingaroundtheroomforthemostcomfortableseat.Somewillchoosethecouch,othersmightchoosetherockingchair.

Inthiscase,theproteinandgreasepartsfindthebottom,waterylayerthemostcomfortableplace,whiletheDNAprefersthetop,alcohollayer.

DNAisalong,stringymoleculethatlikestoclumptogether.

Congratulations!YouhavejustcompletedaDNAextraction!

Nowthatyou"vesuccessfullyextractedDNAfromonesource,you"rereadytoexperimentfurther.Trytheseideasorsomeofyourown:

• ExperimentwithotherDNAsources.WhichsourcegivesyouthemostDNA?Howcanyoucomparethem?
• Experimentwithdifferentsoapsanddetergents.Dopowderedsoapsworkaswellasliquiddetergents?Howaboutshampooorbodyscrub?
• Experimentwithleavingoutorchangingsteps.We"vetoldyouthatyouneedeachstep,butisthistrue?Findoutforyourself.Tryleavingoutasteporchanginghowmuchofeachingredientyouuse.
• DoonlylivingorganismscontainDNA?TryextractingDNAfromthingsthatyouthinkmightnothaveDNA.

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