Fig. 1.

Schematic diagram showing the proteomic analysis of the sperm cells and seminal plasma. After collection and liquefaction of ejaculated semen, the desired target components are purified through density gradients centrifugation. Proteins are extracted and separated by two-dimensional polyacrylamide gel electrophoresis (2D–PAGE) or liquid chromatography(LC), and then followed by identification using mass spectrometry and database search