I have an antibody binding generic protein and I need to compare its activity in a free and immobolized form. I understand that there are a number of methods to determine Kd value of a free protein (BLI or SPR), however I need a method where I can use the same technique for the free and immobolized protein. Initially I was going to use BLI, but one professor said its very difficult to use it for immobolized protein.
My purpose is to prove that immobolized protein has a higher binding affinity towards certain antibodies compare to the free one, at least its supposed to act this way.