Contributions of immunoaffinity chromatography to deep proteome profiling of human biofluids

• The enormous dynamic range of protein concentrations in human biofluids represents a significant analytical challenge for biomarker discovery.
• Immunoaffinity chromatography has become an essential method for enabling the detection of low-abundance proteins in human biofluids.
• The advances of immunoaffinity chromatographic methods including immunodepletion and immunoenrichment are reviewed.
• Proteomics applications of immunoaffinity approaches to human biofluids are highlighted.

Human biofluids, especially blood plasma or serum, hold great potential as the sources of candidate biomarkers for various diseases; however, the enormous dynamic range of protein concentrations in biofluids represents a significant analytical challenge for detecting promising low-abundance proteins. Over the last decade, various immunoaffinity chromatographic methods have been developed and routinely applied for separating low-abundance proteins from the high- and moderate-abundance proteins, thus enabling much more effective detection of low-abundance proteins. Herein, we review the advances of immunoaffinity separation methods and their contributions to the proteomic applications in human biofluids. The limitations and future perspectives of immunoaffinity separation methods are also discussed.