A Biomedical Scientist has been asked to prepare DNA samples from cells isolated from a tumour biopsy. After following the standard protocol for the DNA extraction in the laboratory, the scientists eluted the final DNA sample in 20 μl of elution buffer and measured absorbance at 260 nm and 280 nm. Values obtained are as follows:

A260=1.446

A280 = 0.784

Based on the data above,

A) Briefly describe the protocol for DNA isolation.

B) Comment on the purity of the DNA sample obtained. Provide appropriate calculations to back up your comment.

C) Assuming a pure solution of double-stranded DNA has a concentration of 50 µg/ ml and A260 of 1.0, calculate the concentration of DNA in the solution obtained by the scientist and give the total DNA yield.

D) How can the scientist assess DNA breakage in the sample obtained?