Semen quality assessments and their significance in reproductive technology

Semen quality assessment methods are very important in predicting the fertilizing ability of persevered spermatozoa and to improve animal reproductive technology. This review discusses some of the current laboratory methods used for semen quality assessments, with references to their relevance in the evaluation of male fertility and semen preservation technologies. Semen quality assessment methods include sperm motility evaluations, analyzed with the computer-assisted semen analysis (CASA) system, and plasma membrane integrity evaluations using fluorescent stains, such as Hoechst 33258 (H33258), SYBR-14, propidium iodide (PI), ethidium homodimer (EthD) and 6-carboxyfluorescein diacetate (CFDA), and biochemical tests, such as the measurement of malondialdehyde (MDA) level. This review addresses the significance of specific fluorochromes and ATP measurements for the evaluation of the sperm mitochondrial status. Laboratory methods used for the evaluation of chromatin status, DNA integrity, and apoptotic changes in spermatozoa have been discussed. Special emphasis has been focused on the application of proteomic techniques, such as two-dimensional (2-D) gel electrophoresis and liquid chromatography mass spectrometry (LC-MS/MS), for the identification of the properties and functions of seminal plasma proteins in order to define their role in the fertilization-related processes