Figure 1. Immunoblotting analysis of 2M6 antigen purified from chick retina. Proteins obtained from embryonic day 13 chick retina were subjected to affinity purification using the 2M6-specific antibody conjugated to cyanogen bromide-conjugated (CNBr)-activated sepharose 4B. The eluate was subjected to SDS–PAGE and subsequent immunoblotting analysis using the 2M6-specific antibody. Signals were observed for polypeptides at ~40 kDa, ~46 kDa, and ~80 kDa. These polypeptides were subjected to in-gel trypsinization and subsequent mass spectrometry analyses. Lanes 1 and 2 show duplicate samples of the eluted fraction with the highest absorbance measured at 280 nm.