Differential Extraction

Question 1

What is differential extraction?

Answer 1

the process in which DNA from two different cell types ca be extracted to isolate each fraction

Question 2

What is the difference for sperm cell types compared to epithelial?

Answer 2

Sperm cell types have membranes that are more resistant to epithelial cells

Question 3

How does differential extraction differ from basic extraction?

Answer 3

It lyses the non sperm cells first and then removes the non sperm DNA prior to lysing the sperm cells. this is possible because sperm cells have a stronger cellular membrane. Abnormal wear sperm cells may have a chance of lysing during the initial digestion

Question 4

What are the reagents necessary for differential extraction?

Answer 4

For the initial digestion, G2 and PK are necessary. For the second digestion on F2, the basic extraction reagents are used

Question 5

What is G2?

Answer 5

Buffer G2 is a lysis buffer that is less harsh than ATL

Question 6

What are the digestion requirements for F1 in differential extraction?

Answer 6

2 hours digestion time, 50 C, NO SHAKING

Question 7

How many times is F2 washed on the QiaCube robot?

Answer 7

4 times

Question 8

What protocols for extraction are used for F1 and F2?

Answer 8

F1 large volume RT; F2 trace

Question 8

What reagent is necessary for the breakdown pf sperm cells?

Answer 8

DTT

Question 9

What is the difference between sexual assault swabs and regular casework swabs?

Answer 9

We retain all swabs from sexual assault differential samples