Patent ID: 7070949

Claim:
Method for the analysis of a mixture of different proteins by mass spectrometry, comprising: a) digesting the different proteins in the protein mixture with a common enzymatic digestion; b) separating chromatographically the mixture of digestion peptides; c) collecting individual chromatographic fractions; d) preparing samples on a sample support, wherein the samples contain the digestion peptides from the fractions together with a matrix substance; e) ionizing the digestion peptides from the samples by matrix assisted laser desorption in a time-of-flight mass spectrometer, and measuring the times of flight to determine the masses of the digestion peptide ions; f) measuring the daughter ion spectra of at least some digestion peptide ions from selected samples by MALDI tandem time-of-flight mass spectrometry; and g) identifying the associated proteins by searching in at least one of a protein sequence, cDNA or DNA database.