[A method of determining dehydrogenase activity of human spermatozoa]

The authors present a quantitative method for the evaluation of biologic activity of human spermatozoa by determining their dehydrogenase activity by tetrazolium salts. The method is based on the property of these salts to change during biochemical reduction from colorless water soluble compounds into insoluble compounds in water compounds (phormazanes), which remain at the site of the reduction, e.g. in the cell. Most of the phormazanes are extracted by organic solvents (ethanol) and determined quantitatively by a spectrophotometer. We have measured dehydrogenase activity in spermatozoa by the amount of phormazane, obtained from a number of cells for a fixed time. We propose for determination of dehydrogenase activity in human spermatozoa: triphenyltetrazolium chloride, temperature of incubation at 37 degrees C, stopped by enzymic reaction by formaline, and creation of anaerobic conditions for incubation with Na2SO3.