The interconversion of machine settings and size determinations between seven models of Coulter counter as illustrated by values for human spermatozoa

Measurements of membrane potential of human sperm using electrode sensitive to tetraphenyl phosphonium cations

For the first time, an attempt was made to measure the transmembrane potential of human spermatozoa by an electrode sensitive to the lipophilic cation tetraphenyl phosphonium (TPP+). However, the assumption of a single correlation between the decrease of the TPP+ concentration in the medium and metabolism-dependent membrane potential cannot be confirmed. The participation of different processes is very likely. Artificially damaged spermatozoa showed an enhanced affinity to TPP+ (the stronger the damage, the stronger the affinity of the spermatozoa to TPP+), but there were no significant differences of the cellular affinity to TPP+ between fresh and cryopreserved spermatozoa.

Computer-aided counting with the Coulter Counter of low numbers of spermatozoa in human semen

The concentration of spermatozoa in human semen has been assessed by counting in the microscope with a hemocytometer and by counting with the Coulter Counter ZF. The Coulter Counter was supplied with a 100-channel pulseheight analyzer, Channelyzer C-1000, and a tape-punch for further handling of data in a desk-computer. It was found that the number of spermatozoa (less than 10(6) per ml) was over-estimated with the Coulter Counter. By subtraction of the non-spermatozoan background with the aid of mathematical curve-fitting procedures, these values could be corrected. To allow such an adequate analysis without the use of pulse-height analyzer and computer, the background corrections were simulated for the relative number of counts obtained at specified setting of the threshold levels (T) and other variables on the Coulter Counter ZF.

Comparison of the particle size distribution curves determined manually and automatically in an accurately calibrated Coulter Counter

An accurately calibrated Coulter Counter, Model ZB Industrial, was used to compare the size distribution curves of seven different standard particles obtained by calculation and after the attachment of a Channelyser, Model C-1000 coupled to an XY recorder. Comparisons were made at the modes of the curves and it was found that the automatic method consistently reported the particles to be slightly larger.