The activation of folic acid, come soon!pH value, EDC/NHS

Folic acid activation is useful for DCC/NHS. EDC/NHS is also used. The carboxymethyling base shell polycosan of the polymer, but it is insoluble in PH4.7-6!The EDC/NHS catalysis is between 4-6!Also, I activate folic acid in DMSO, which is difficult to grasp the catalytic ratio. Finally, what is the reason why the carboxymethylene basal shell poly aquaculture solution directly deforms frozen -like?I used EDC hydrochloride, and I used to use EDC to not occur. This is not the case.Can you analyze it for me?