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DNA EXTRACTION

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Experiment Four

In this experiment I varied the temperature of the alcohol used to precipitate the DNA to see if the amount of DNA extracted would change. The temperatures used in this experiment were 4.5C (stored in fridge) and 21.5C (stored at room temperature).  I will also compare the results to the the extraction in Experiment One where the alcohol temperature was -15 C.

Alcohol 4.5 C (Fridge Temperature)

DNA Source

Observations 

( immediate)

Observations 

(taken 24 hours later)

Green Peas (soaked overnight) DNA appeared immediately, forming stringy, upward strands. DNA has formed thin, stringy shapes that look like roots.
Yellow Peas (soaked overnight) DNA appeared immediately, forming thick swirls.  DNA was produced on the top of the test tube in a cylinder-like form and a stringy shape just above the peas.
Chick Peas (soaked overnight) DNA appeared immediately at the surface forming small globs. In two test tubes DNA formed in large, thick layers. In the other test tube DNA floated to the top a small cylinder shape. 
Onion DNA formed slowly, forming what looks almost translucent and ice-like. Small amounts of DNA were produced. Small cylinder-shaped blobs were formed at the top of the test tube.
Parsnip DNA appeared at the surface of the test tube almost immediately in thick globs. Many thick, fat globs were produced form the top of the test tube to just above the parsnip.

After the last written observations were made, DNA sources in each test tube were carefully removed and weighed.

DNA sources measured in gm     Temperature of Alcohol 4.5C

Source

1

2

3

Total in gm

Average in gm

Green Peas

1.84

1.31

0.91

4.06

1.35

Yellow Peas

1.46

1.57

1.76

4.79

1.60

Chick Peas

1.07

1.12

1.92

4.11

1.37

Onion

0.84

0.66

0.51

2.01

0.67

Parsnip

0.64

0.53

0.47

1.64

0.55

 

 

Alcohol 21.5 C (Room Temperature)

DNA Source

Observations 

( immediate)

Observations 

(taken 24 hours later)

Green Peas (soaked overnight) DNA formed immediately in the test tubes. DNA floated to the top of the test tubes.  There are three different forms of DNA in these test tubes. In test tube no. one, there are stringy strands of DNA. In test tube no. two there is a thick, cylinder-like shape of DNA. In test tube no. three there is a stringy-like ball of DNA. (I haven't seen this form of DNA yet).   
Yellow Peas (soaked overnight) DNA formed immediately in one big glob of DNA in one test tube and not as big globs in the other two test tubes. DNA looks like roots or icicles and are translucent. 
Chick Peas (soaked overnight) DNA formed a very thin layer of DNA at the top of the test tubes. Cylinder-shaped globs of DNA formed at the top of the test tubes with roots leading downward but not very far. The is also sort of spikey-looking.
Onion Not too much DNA formed in the test tubes. The DNA that has formed in the test tubes floated to the top in an extremely tin layer. (Very similar to the fridge temperature version of the onion). The DNA is small, slushy, cloudy, forming from the middle to top of test tubes
Parsnip DNA has not rose to the surface but did form a thin layer of DNA just above the parsnip in the test tubes. No DNA formed

After the last written observations were made, DNA sources in each test tube were carefully removed and weighed

DNA Sources in gm      Temperature of Alcohol 21.5C

Source

1

2

3

Total in gm

Average in gm

Green Peas

1.37

1.28

1.06

3.71

1.24

Yellow Peas

1

0.92

1.77

3.69

1.23

Chick Peas

1.01

0.88

1.08

2.97

0.99

Onion

0.61

0.44

0.53

1.58

0.53

Parsnip

0.68

0.92

0.75

2.35

0.78

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