what is OD in terms of HPLC? - (Mar/15/2013 )
what does this mean-
Exactly what you said - it is the fraction, they have collected it to give an OD of 15 -so probably an awful lot of protein going through.
(i'm really picking nits here) od at 260 would be for nucleic acids
Yes mdfenko, you are right , it is about nucleic acids. @bob, I checked about yields of nucleic acids, they calculate in terms of OD, if you just check synthesis of nucleotides, you will get to know. I am still struggling to calculate concentration, when od is given.
For dsDNA the calculation is quite simple e.g. (copied from cold spring harbour protocols)
Example of Calculation
A sample of dsDNA was diluted 50X. The diluted sample gave a reading of 0.65 on a spectrophotometer at OD260. To determine the concentration of DNA in the original sample, perform the following calculation:
dsDNA concentration = 50 μg/mL × OD260 × dilution factor
dsDNA concentration = 50 μg/mL × 0.65 × 50
dsDNA concentration = 1.63 mg/mL