Reversed-phase high-performance liquid chromatographic prefractionation of immunodepleted human serum proteins to enhance mass spectrometry identification of lower-abundant proteins.

Serum analysis represents an extreme challenge due to the dynamic range of the proteins of interest, and the high structural complexity of the constituent proteins. In serum, the quantities of proteins and peptides of interest range from those considered "high abundance", present at 2-70% by mass of total protein, to those considered "low abundance", present at 10(-12) M or less. This range of analytical target molecules is outside the realm of available technologies for proteomic analysis.