The identification of conformational-dependent and -independent MAbs.

Samples (100 μL) of either untreated (native) or SDS/β-mercaptoethanol and boiled (denatured) CEACAM1-4-Fc soluble recombinant proteins at concentrations of 100 ng/100 μL (1) and 10 ng/100 μL (2) were slot blot transferred onto immobilon-PVDF membranes and their reactivities with the CD66/CEACAM MAbs determined as described in “Materials and methods.” NCAM(D1-7)-Fc was used as a negative control and did not bind the CD66/CEACAM MAbs (data not shown). This experiment was repeated at least twice for each MAb.