A: Colour scheme coded slope coefficients c 1 of the MME determined by the peptide rule based calibration method. B: The slope coefficient as predicted from the refined samples determined by TPS with λ = 0.001. C: Strip chart of the data set for a mass range of 2210 – 2212Da (C1) and 842 – 843Da (C2), including the tryptic autolysis peaks 842.508 and 2211.100Da. Black crosses – masses of peaks predicted by the peptide rule based calibration method, red circles – masses predicted by the TPS calibration method. Vertical blue line – exact position of trypsin autolysis masses 842.508 and 2211.100Da. Dashed red vertical line – mass of the extreme peptide masses after TPS calibration.