Determination of human sperm count and sperm motility using a laser beam and the Doppler effect (LAZYMOT machine).

For 25 consecutive human semen samples, a comparison was made of sperm count and sperm motility values obtained by routine manual methods and by using a machine that measures these functions by analysing the deflection of an impinging laser beam (Lazymot machine). Sperm counts in undiluted semen were approximately 5 times higher with the laser machine. As sperm counts increased to about 300 million/ml the counts obtained by the two methods converged as the chance of the beam hitting a spermatozoon and not another type of particle increased. In semen diluted 1 + 4 with Baker's solution, the uncorrected laser count agreed well with the sperm count obtained using a haemocytometer. Multiplication of the laser count by 5 did not reach the same count as that measured in the undiluted sample, showing that the dilution had dissolved some of the smaller particles. It was recommended to measure laser percentage motility in undiluted semen but the values obtained bore no relationship to those obtained using a haemocytometer and neither did the values obtained for laser percentage sperm with progressive motility. The mean laser velocity of the total motility was 23-64 micron/sec and for the progressive particles was 48-84 micron/sec, values which were much faster that the acceptably normal values of 8-30 micron/sec found for selected progressively motile spermatozoa timed with a stopwatch. The laser machine detected an increase in counts and the presence of residual motility after cytoplasm had been stripped away from the spermatozoa with a saponin reagent. The laser machine was unable to detect any increase in speed on increasing the temperature to 37 degrees C. It was concluded that the Lazymot machine as presently designed is not useful in the andrological laboratory for routine counting and motility determinations, mainly due to the absence of a size discriminator against the multitude of small particles that are present in human semen.