Hello, I am planning to carry out an conjugation reaction between two purified proteins (P1: 59.8KDa and P2: 32.8KDa) to observe the conjugation efficiency on an SDS-PAGE gel. I want to carry out the reaction P1:P2 in 2:1 molar ratio, but my total protein in the reaction should be only 4ug. 

Would anyone please suggest me what is best way to calculate the mass of the proteins to equalize to my molar ratio or what is the best way to setup the conjugation reaction with the total protein in the reaction is only 4ug?

Thanks for suggestions and time.