Do I have to use a blank on my microplate when quantifying DNA at 260 nm?
Where A is absorbance (no units), ε is the molar absorbtivity (L mol-1 cm-1), b is the path length of the sample (cm), and c is the concentration of the compound in solution (mol L-1).
Since most things in nature absorb light, including the plastic in the microplate and the DNA buffer (i.e. water or TE), a blank well with just these components should be subtracted from a well that also has DNA. After blank subtraction, only DNA will contribute to the “A” variable in Beer’s law above.
To learn more about quantifying DNA using a microplate (96- and 384-well), a cuvette, or the LVis Plate, please see our Technical Application Note 001.