FIGURE 1.

Silver-stained one-dimensional-SDS-PAGE of the guanidine-soluble protein extract of normal young (n = 3) and old (n = 3) tendon and diseased young (n = 3) and old (n = 2). Equal protein loading by volume (20 μl per well) allowed a qualitative comparison of soluble tendon protein extracts. The most abundant protein bands are marked with red squares (1–4) were excised from the gel and trypsin-digested, and the protein content of each single band was analyzed from peptides identified using LC-MS/MS. The black square highlights the additional bands evident in diseased young tendon only.