Protein diversity in biological systems is quite large, but short term (<1hour) changes due to a particular stimulus will cause A only subtle changes in very specific proteins expression levels. Excessive sample handling/processing methods often add significant noise to overall experimental results. Here we use a combination of simple sample preparation technique, extremely reproducible UHPLC system and a robust mass system, t t l tf t ff d h th bilit t spectrometer platform to afford researchers the ability to use massive protein/peptide libraries for quantification of several thousand proteins.

　　To study the effectiveness of this method, a model system using whole live bacteria, both gram negative and positive strains, were spiked into whole blood samples from a single donor. After 1 hour, plasma and peripheral blood mononuclear cells were isolated and analyzed for protein expression differences.