Question

Can someone help me interpret our reading into context and answer the following questions related.

Proteins and phenol absorb ultraviolet light. Both have absorption peaks between 260 and 300 nm. What would contamination with protein and/or phenol do to the ratio A260/A280? If your DNA solution was contaminated with protein and/or phenol, what would happen to the peak of the absorption curve (relative to the peak of a curve for pure RNA/DNA)? Does your DNA-solution seem to be contaminated with protein and/or phenol? Justify your answer.

Answer 1

Lamda 230 value show contamination of phenol

While lamda 260 shows presence of DNA, while A280 showed contamination of both Protein and phenol both.

Low A260/A280 value (below than 1.5) shows contamination of protein while we need to check A260/A230 if it's value greater than 2 which means no contamination of phenol,pure DNA is present.

If multiple peak form than we can assume that it's due to phenol or other contaminant.

Here A260/A280 showed 1.02 means DNA is contiminated with protein. A280 showes clearly presence of protein as it's value is 1.16.

Also, there is presence of phenol as at A230nm showed 0.954 the presence of phenol contamination.

So final conclusion is that DNA is not pure it has contamination of both protein and Phenol which can be removed by treating with cleanup solution.

Hope it's clear.. thanks