skin testing will test for a couple of isolated milk proteins (like casein) as well as whole milk. the pharmacia website lists the various milk "components" that they can specifically look at w/ the CAP RAST.... Marla Shapiro, Ph.D. Department of Psychology Georgia State University Atlanta, GA 30303 >>> [log in to unmask] 08/14/02 01:02AM >>> I just seen discussion of being allergic to casein or whey or both. Perhaps this i= s=20 the answer here. Can they test to see which protein it is that he is=20 allergic to? Can we do this with a RAST? =20 E.J.