Buffering capacity of human semen.

The buffering capacity of 270 semen samples derived from 196 men of infertile couples was determined from titration curves. The average buffering capacity in the physiologic range (pH 7.0 to 6.0) was 41.1 slyke (standard deviation [SD], 9.9), which is significantly higher (P less than 0.01) than that in serum (23.3 slyke; SD, 7.5; n = 42). When the buffering capacity of several semen samples of one man in the course of time was measured, the variation between these samples was larger than the determination error. No correlation was found between the buffering capacity of serum and semen of the same man, nor between the buffering capacity of semen and the fertility grade determined by physical and morphologic analysis of the samples.