Relative ratios of lactoferrin, albumin, and acid phosphatase seminal levels as sperm quality markers in fertile and infertile men.

Human seminal plasma proteins from fertile and infertile men were fractionated by electrophoresis. The amounts of three Coomassie-stained protein bands were measured by densitometry. Their relative ratios were constant in normospermic men but varied in the infertile patients. Laboratory manipulation of the semen was shown not to affect the protein ratios as observed after liquefaction, incubation at various temperatures, and storage at -20 degrees C. The three proteins were purified by chromatographic techniques and identified as lactoferrin, albumin, and acid phosphatase by electrophoresis, high-pressure liquid chromatography, and enzyme assays. The use of these proteins to evaluate the contributions of different fluids to seminal plasma is discussed.