What is the smallest quantity of DNA that can reasonably be measured with the BioPhotometer?
The BioPhotometer should not be used to measure an absorbance of less than 0.05 at 260 nm. This OD value corresponds to a dsDNA concentration of app. 2.5 µg/ml (= app. 125 ng dsDNA in a 50 µl preparation). Please note that you should measure at 260 nm for a minimum absorbance of 0.1 in order to obtain exact results.