THE PERFORMANCE OF 10 DIFFERENT METHODS FOR THE ESTIMATION OF SPERM CONCENTRATION

Objective: To evaluate the performance of different methods of sperm c ounting using latex beads and sperm suspension. Design: A quality-cont rol study. Setting: University-based andrology laboratory. Interventio n(s): None. Main Outcome Measure(s): Counting latex beads six times in two standard suspensions using 10 methods and counting spermatozoa wi th 4 methods. Result(s): When air-displacement pipettes were used, the disposable chambers Standard Count (Leja, Amsterdam, Holland), Cellvi sion (Anthos-ec, Heerhugowaard, The Netherlands), and Cell Vu (Fertili ty Technologies, Inc. Natick, MA) showed small variation and correct e stimation of bead concentration. All the reusable chambers gave relati vely large variability, with tendency to underestimate (improved Neuba uer; Hawksley, Lancing, United Kingdom) or to overestimate the bead co ncentration. The use of plunger-displacement pipettes resulted in an o verestimation of bead concentration in medium but not in seminal plasm a. Counting the sperm suspension using plunger-displacement pipettes i ndicated that the Burker hemocytometer overestimated concentration rel ative to that obtained by Cellvision and Makler Counting Chambers (Sef i Medical Instruments, Haifa, Israel) and that the improved Neubauer p resented the lowest variability (7.1%). Conclusion(s): The improved Ne ubauer hemocytometer is the standard for sperm counting, though dispos able chambers give reliable results as well. If beads are used to eval uate the accuracy of counting chambers, it is recommended to dilute th em with seminal plasma. (C) 1997 by American Society for Reproductive Medicine.