Cumulative number of MS/MS spectra versus the number of unique peptide identifications with P > 0.9. The slope is nearly horizontal in regions of the curve where similar experiments were performed. The curve is expected to show saturation when additional spectra provide no new peptides above P > 0.9. The number of distinct peptides from an in silico trypic digestion of the SGD protein database, allowing one missed cleavage, and counting those peptides whose masses are in the range 500 to 4,000 Da, is 436,445.
King et al. Genome Biology 2006 7:R106 doi:10.1186/gb-2006-7-11-r106