Histogram plots of immunodepleted proteomic samples. Sample sets early osteoarthritis (EOA) 1–5 are biological replicates from early-stage OA patients and sample sets late OA (LOA) 1–4 are biological replicates from late-stage OA patients. Log2 of protein ratios and normalized protein ratios are plotted on the x axis and estimated densities of log ratios on the y axis. The black curve represents experimental protein regression ratios; red and blue curves represent normalized ratios for early and late sample sets, respectively.
Wanner et al. Arthritis Research & Therapy 2013 15:R180 doi:10.1186/ar4369