In this whitepaper, we quantified the amount of amplicon formed as a function of the amount of input biotinylated nucleotide by gel densitometry. In particular, the percent amplicon yield for a given percentage of biotinylated nucleotide was normalized to an reaction which contained only natural nucleotides.
While this approach can be used to identify optimal reaction conditions that will allow for biotinylated nucleotide incorporation in PCR without sacrificing amplicon yield, this does not measure the amount of biotin in the PCR product itself. Should direct quantification of the biotin content be of interest, enzymatic digestion of the isolated product is one way to do this. Eadie, et. al.and Andrus, et. al.describe this technique in their publications.