[Protein-analysis] How to determine the number of primary amino groups on a virus surface

[Zhenkun Zhang]

Hi! Folks!

I have modified some coat proteins of a virus. I want find some way to
see the difference of the number of the primary amino groups  between
intact and modified virus. I tried the TNBS method but got no
reasonable results. Is there orther nice way? As for  TNBS method, do
you have any tipps?

Thanks!