Hi,

I am having trouble with this calculation to perform a conjugation.

I need to perform a strevptavidin conjugation to biotinylated-completment. For example, the biotinylated complement is 3"BiotinXXXXXXX" at 200uL of 500uM Stock.

I know streptavidin consists of 4 subunits with a MW of 13000, each containing a single biotin binding site. The molar ratio of 1 mole of streptavidin +4 moles of biotinylated molecule (assuming I have 1 biotin/mole of molecule).The Streptavidin stock comes in at 10mg/mL. I have 100uL of it. (1mg total)

What is the calculation I should use to get the right ratio? Do I have to incorporate Avagadro's number to find the right ratio?

Thanks for any assistance.