How much antobody to bind to bacterial culture? - (Nov/15/2007 )

I would like to bind a certain antibody to a bacterial culture to test whether I will inhibit a certain event. But I am not sure how much of the antibody is usually enough and how to be sure that the amount was enough if the result happens to be negative?

try a range of antibody concentrations (over a couple of logs). it would also help to know the approximate protein content of the culture and the antibody solution to determine the starting range.