Figure 4. Coomassie blue-stained gel from 2D-DIGE of 69-year-old human lens. The gel was stained with Coomassie blue R250 for the purpose of manually picking the individually labeled spots (circled and numbered in the figure) for identification by ESI-QTRAP LC/MS/MS. The gels in this figure are technical replicates, so corresponding spots were picked and pooled for identification.