Avery, Mcleod & McCarty Flashcards
1
Q
What did they do?
A
- Isolated DNA from the dead S-strain of bacteria split them into 2 test tube:
- Purified the DNA so that no protein was present and found that this extract would transform the non-virulent R-strain into the S-strain
- Next, they extracted deoxyribose nuclease enzyme from dog and rabbit blood and used it to digest DNA (removed it)
- Added R-strain, no S-strain occurred (no transformation)
2
Q
•The digested DNA would not…
A
transform the non-virulent R-strain into the S-strain - concluded DNA was the ‘transforming principle’
3
Q
What did they use?
A
- Cell-free extract of s cells
- From 75L or cell culture obtained 10-25 mg of “active factor”
- Proteases, RNases, DNases, etc
