This might have occurred because the viral coat protein may have denatured and epitopes were not preserved in the original conformation in presence of the high pH of the coating
buffer in PTA-ELISA and SDS in the Western blot. In DAS-ELISA, two MAbs G10 and C11 were identified which recognized CiLV-C in crude extracts of CiLV-C infected tissues. The MAbs G10 and C11 recognized the unique conformational epitopes in the coat protein of CiLV-C virion but G10 only worked as a capturing antibody and C11 worked only as the detection antibody. This enabled the development of a DAS-ELISA using G10 as the coating (capture) MAb and C11 as the AP-conjugated detection MAb with increased specificity for CiLV-C detection from crude extracts. Coat protein p29 of CiLV-C could not be detected with the conjugated MAb-C11 ifthe virus was
first captured with the other MAbs analyzed (C11, E10 and F9). One could speculate that the conformation of the CiLV-C coat protein may be altered after binding these MAbs resulting in the epitope specific for C11 being unavailable for binding and perhaps is only be exposed when CiLV-C is first bound with MAb-G10.