I have a problem and need your help!
In our lab we tried to extract genomic DNA from lung epithelial cells (A549) with the phenol:chloroform protocol.
I thought that everything was under control until we measured the optical density of the final DNA solution.
This is what we had:
260nm = 0.155
280nm = 0.132 (260/280=1.17)
235nm = 0.044 (260/235=3.52)
I think that the above ratios should be ~1.8 in pure DNA.
Do you have any idea what went wrong here? Is this an evidence of contamination? And if yes, what kind of contamination it could be?
I would appreciate every answer! Thank you soooo much!