Immunoblot analysis of lens membrane fractions isolated from 20-day-old rats. (A) Lens membrane fractions separated by electrophoresis through 5-20% gradient gels were transferred to PVDF and immunoblotted with MAb 10A5. WSF: water soluble fraction, 10 μg. NSMF: non-sedimenting membrane fraction, 5 μg. 25/45 fraction, 5 μg. (B) A duplicate gel was stained with Coomassie Blue R-250. Note that the 10–15 kD antigen reactive with MAb 10A5 did not stain with Coomassie Blue (area marked by the asterisk), although numerous proteins outside that mass range took up the dye. Molecular weight standards (Mr) are Bio-Rad Precision Plus dual color markers (5 μl) and are expressed in kD.