What is the dilution factor if 2 μl of DNA sample is added to 498 μl of water (Dilution factor = Final volume / Aliquot volume)? If the A260= 0.2 for the diluted sample, what is the concentration of DNA in the undiluted sample in μg/μl

The correct answers are: Dilution factor = 250 and concentration of DNA in undiluted sample = 2.5 μg/μl.

Explanation:

Volume of DNA taken = 2 μl.Volume of added water = 498 μl.Total volume of the sample = 2 μl + 498 μl = 500 μl.Dilution factor = A₂₆₀ of the given sample is = 0.2.We know that 50 μg/ml concentration of pure double stranded DNA gives an absorbance, A₂₆₀ = 1.Again, Concentration of DNA(µg/ml) = µg/ml.                                                             = μg/ml.In order to convert it into μg/μl, we have to divide the above value by 1000, hence we get, μg/μl.