Figure 3. 2-D Electrophoresis map showing identities of lens nuclear water-soluble proteins of a 2.5-month-old guinea pig. The major proteins of the lens nucleus were identified by matrix assisted laser desorption (MALDI) mass spectrometry. αA-crystallin was far more abundant than αB-crystallin (ratio of 8:1) as quantified by image analysis software, Image J. All β-crystallins (βA1-, βA2-, βA3-, βA4-, βB1-, βB2-, and βB3-crystallin) and γA-, γB-, and γC-crystallin were detected on 2-DE gels, but no protein signatures were found for γD-, γE-, or γF-crystallin. The gel contains 53 spots, 44 of which have been identified as various intact or truncated crystallins. Proteins were stained with Coomassie Blue G-250.