Question

Role of phenol chloroform dna extraction protocol from blood

Answer 1

A pellet of white cells should form at the bottom of the tube. ... Incubate over night at 37oC or at 55oC for 4-5 hours, after which the solution should be less viscous, due to the white blood cells being broken down. Check that the sample has been lysed adequately before proceeding with the phenol-chloroform extraction.

Answer 2

The purpose of adding chloroform along with phenol is to ensure a clear separation between the aqueous and organic phases. ... This is useful for when the aqueous phase is removed from the solution in order to obtain a pure nucleic acid sample. pH is an important factor to consider in the phenol extraction technique.
To get at it, scientists first spin a small sample of your blood at high speed, to separate the cells from the blood fluid. Next, they release the DNA from the cells using a detergent and a special enzyme. Finally, they add alcohol, which makes your DNA appear as sticky blob in the mixture.

Hope this will help u... :-)