DNA DNA EXTRACTIONEXTRACTION

JAN 24, 2013JAN 24, 2013

Lab # 33Lab # 33

I.I. Background Background InformationInformation

*Strawberries are octoploid, which *Strawberries are octoploid, which means they have eight sets of means they have eight sets of chromosomes. The procedure for chromosomes. The procedure for extracting DNA from a strawberry is extracting DNA from a strawberry is simple, and the results are usually simple, and the results are usually obvious, it is easy to see the white obvious, it is easy to see the white strands of DNA within the pink solution strands of DNA within the pink solution of strawberry juice.of strawberry juice.

This process is DNA fingerprinting, It is This process is DNA fingerprinting, It is what Forensic Scientists do.what Forensic Scientists do.

I.I. QuestionQuestion

What does DNA Look like?What does DNA Look like?

II.II. HypothesisHypothesis

If… Then… because…If… Then… because…

III.III. MaterialsMaterials

See Student Manual Page 19 or look See Student Manual Page 19 or look at materials you use at materials you use

Make sure to write down all Make sure to write down all materialsmaterials

IV.IV. DNA Extraction Techniques DNA Extraction Techniques Procedure : Extraction from Procedure : Extraction from

StrawberryStrawberry DNA Extraction BufferDNA Extraction Buffer (can be prepared in advance) (can be prepared in advance) 900 ml of deonized water, 50 ml of clear dishwashing 900 ml of deonized water, 50 ml of clear dishwashing

detergent, 2 teaspoons of saltdetergent, 2 teaspoons of salt 1. Add a strawberry (or half a strawberry) to a ziploc 1. Add a strawberry (or half a strawberry) to a ziploc

storage back and use your hands to smash (Maceration) the storage back and use your hands to smash (Maceration) the strawberry, taking care to not break the bag.strawberry, taking care to not break the bag.

2. Add 10 ml of the DNA extraction buffer (Lysis Solution).2. Add 10 ml of the DNA extraction buffer (Lysis Solution). 3. Smush (Macerate) the strawberry and buffer for one 3. Smush (Macerate) the strawberry and buffer for one

minute.minute. 4. Use a coffee filter, cup, and rubber band to filter the 4. Use a coffee filter, cup, and rubber band to filter the

strawberry juice into a single cup and then pour into a strawberry juice into a single cup and then pour into a single test tube.single test tube.

5. Slowly pour cold ethanol or 91% isopropyl alcohol (7-5. Slowly pour cold ethanol or 91% isopropyl alcohol (7-10mls) over the top of the strawberry mixture. You want a 10mls) over the top of the strawberry mixture. You want a single layer of clear ethanol on top of the strawberry single layer of clear ethanol on top of the strawberry mixture. COLD ethanol will work best- It condenses the mixture. COLD ethanol will work best- It condenses the DNA.DNA.

6. White strands will form in the ethanol layer, use a 6. White strands will form in the ethanol layer, use a stirring rod to spool the strands.stirring rod to spool the strands.

V.V. DataData

This will be a drawing of the DNA This will be a drawing of the DNA when you have completed the labwhen you have completed the lab

_____________________

_____________________

0 X Actual Size

STRAWBERRY DNA

V.V. Data AnalysisData Analysis

1. Why do you think we added the 1. Why do you think we added the Lysis solution?Lysis solution?

2 Why does the isopropyl alcohol 2 Why does the isopropyl alcohol need to be cold?need to be cold?

3. Where do you find DNA?3. Where do you find DNA? 4. What does DNA look like?4. What does DNA look like?

VI.VI. ConclusionConclusion

Next time I would….Next time I would…. Today I learned….Today I learned…. My hypothesis was ….My hypothesis was ….

VocabularyVocabulary 1- Lysis 2-Masuration 3- 1- Lysis 2-Masuration 3-

SpoolingSpooling