Molarity of 1 μg/μl solution:
Number of molecules in 1 μg:
Approx. 260 nm extinction coefficient:
A260 of 1 μg/μl solution after 100-fold dilution:
In the following lines, fill in two out of the three fields and click 'Calculate'.
Absorbance and concentration
In a 1 cm cuvette, 260 nm absorbance after dilution by factor corresponds to original concentration of μg/μl.
Empirical rules for the relationship between nucleic acid concentration and 260 nm absorbance (OD260)
OD260 units are sometimes used to describe quantities of nucleic acids. One OD260 unit is the amount of nucleic acid that will give 260 nm absorbance 1 after dissolution in 1 ml of solvent.
Molarity, mass and volume
For micromolar concentration dissolve μg in the volume of μl.
Base-pair molarity of dsDNA solutions
For millimolar concentration of base pairs dissolve μg of dsDNA in the volume of μl.