A Proteomics Tutorial

Abstract

Mass-spectrometry-based proteomics approaches and technologies have been employed in numerous areas of the biological sciences and provided many insights into the composition, function, and regulation of biological systems. Despite this long track record in illuminating biological problems, proteomics is just beginning to gain traction in forensic science. Proteomics approaches can identify unknown proteins and organisms, distinguish between various body fluids and tissues, and provide insight into methods of preparation of unknown biological samples. Because forensic proteomics is a nascent field, the concepts, methods, and vocabulary of proteomics may be unfamiliar to forensic scientists. Furthermore, proteomics is a wide and interdisciplinary field that incorporates many different variations of sample preparation, instrumental analysis, and data analysis. This chapter aims to give a brief introduction to the proteomics family of methods, with a focus on principles that will make the other chapters in this volume more accessible. We emphasize the differences between targeted and untargeted proteomics, the process of peptide identification from tandem mass spectrometry data, and the methods of quantitation. Sample preparation is covered in a later chapter.