European Bioanalysis Forum: recommendation on dealing with hemolyzed and hyperlipidemic matrices.

Recent guidelines on bioanalytical method validation have recommended to investigate matrix effects in special matrices such as hemolytic and hyperlipidemic plasma. However, these guidelines were not clear on how to implement these recommendations. The European Bioanalysis Forum has discussed this topic in depth and has asked for feedback from member companies. Those discussions have resulted in more specific guidance on how to define hemolytic and hyperlipidemic plasma, how to validate bioanalytical methods for these matrices and how to deal with hemolytic and hyperlipidemic study samples. These recommendations are presented in this manuscript.

Enrichment of multiphosphorylated peptides by immobilized metal affinity chromatography using Ga(III)- and Fe(III)-complexes.

The detection and identification of O-phosphorylation sites in proteins with mass spectrometry remains a challenge. A common approach to analyse these modifications is to enrich phosphopeptides by immobilized metal affinity chromatography (IMAC) prior to mass spectrometric analysis. In this study two commercially available IMAC kits based on Fe(III)-ions immobilized on magnetic beads and Ga(III)-ions immobilized on a chelate-resin, have been investigated and the binding efficiency of peptide mixtures containing non-phosphorylated, singly, doubly and triply phosphorylated peptides have been tested.