Which of the following statements about DNA isolation from E. coli is not correct?

a. chemical extraction using phenol removes proteins from the DNA

b. RNA is removed from the sample by RNase treatment

c. detergent is used to break apart plant cells to extract DNA

d. lysozyme digest peptidoglycan in the bacterial cell wall

e. centrifugation separates cellular components based on size

The correct answer is c. detergent is used to break apart plant cells to extract DNA.

Explanation:

Here we are talking about DNA isolation in E. coli and detergent is used to break apart the bacterial cell membrane by destabilizing the cell membrane. Detergent disintegrates the proteins present in the cell membrane which causes the rupture of membrane releasing the cell extract outside the cell.

Detergent is not able to break plant cell because it is made up of cellulose and require blending or mashing. Detergent can only be used to disintegrate the cell membrane because only cell membranes contain lipids and proteins.

Hence, the correct answer is c. detergent is used to break apart plant cells to extract DNA.