Rapid selection of peptide containing fractions in off-line 2-D HPLC in shotgun proteome analysis by screening with MALDI TOF MS.

A simple and fast screening method for the selection of fractions of first dimension separation to be analyzed in second dimension-MS/MS experiments in offline multidimensional liquid chromatographic separation schemes for shotgun proteome analysis was developed. The method is based on the measurement of total peptide content of the first dimension fractions by MALDI MS and was established using a tryptic digest of a bacterial proteome. The results of the screening process were in good agreement with those obtained in a detailed proteome analysis performed by RPxion-pair RP-MALDI TOF/TOF MS analysis. The method supports a straightforward planning of experiments, also enabling a reduction of overall measurement time in shotgun proteome analysis.