Peptide detection significance levels using experimental spectra of the 103 peptides with and without any post-translational modifications (PTMs) against a standard target database across database search programs (OMSSA, X! Tandem, and Crux).

a<p>Significance threshold (t) for matched to be considered significant at an E<i>-value</i> or <i>p-value</i> < 1×10^−t (t = 0 to > = 6).</p>b<p>Cumulative number of peptides with an E<i>-value</i> or <i>p-value</i> < 1×10⁻².</p>c<p>Number of peptides missed by program.</p>d<p>Number of peptides with incorrect post-translational modification assignment.</p><p>Peptide detection significance levels using experimental spectra of the 103 peptides with and without any post-translational modifications (PTMs) against a standard target database across database search programs (OMSSA, X! Tandem, and Crux).