Pooling aqueous humor samples: bias in 2D-LC-MS/MS strategy?

The proteomic analysis of body fluids presents a major challenge in studies of human diseases. Traditional techniques for protein separation require large volumes and large amounts of protein, which may be difficult to obtain for certain fluids, such as the aqueous humor (AH). Two-dimensional liquid chromatography (2D-LC-MS/MS), adapted for peptides separation from complex protein mixtures, provides an alternative approach in proteomic analysis with a potential utility in biomarker research.