Can I use the Nanodrop to measure the concentration of synthetic oligos?

Can I use the Nanodrop to measure the concentration of synthetic oligos?
YES. Nanodrop technology can be used to measure the concentration of individual synthetic oligos using each oligo’s unique analysis constant. By default, the Nanodrop equipment uses a value of "33" as a general constant for all single-stranded DNA, which is inappropriate for synthetic oligos. Oligos purchased through Biosearch Technologies arrive with data sheets containing the extinction coefficient and molecular weight of each oligo. These numbers are used to calculate the analysis constant needed for Nanodrop concentration calculations. Use the formula below to calculate the Analysis Constant(AC):

AC = (1/extinction coefficient) x (Molecular Weight(protonated)) x 1000
= AC in micrograms per OD260nm

When measuring labeled oligos, we have determined through internal research that the Nanodrop's linear range of detection is much more limited than advertised. For oligo stocks in the 100 µM range, the Nanodrop will record an apparent concentration that is significantly below the actual concentration. We recommend diluting such stocks 25-fold to achieve a concentration in the range of 4 µM, and enable accurate measurements.

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