Preanalytical variations have major impact on most biological assays. Specifically MS-based\ud
multiparametric proteomics analyses of blood specimens are seriously affected by limited protein stability due to high\ud
intrinsic proteolytic activity of serum and plasma. However, the direct analysis of sample quality (DASQ) for serum\ud
specimens is not readily available. Here we propose the mass spectrometry based monitoring of peptide patterns\ud
that are ex vivo changing in a time dependent manner to alleviate these constrains