Special Article Freeze-Drying of Bovine Spermatozoa

INTRODUCTION In 1959 the authors published a report of the successful freeze-drying of bovine spermatozoa (Meryman & Kafig, 1959). With one exception other investigators were unable to reproduce these experiments in their own laboratories although several duplicated the results in the authors' laboratory. This paradoxical situation was further complicated as the authors themselves experienced increasing difficulty in duplicating their past experiments leading ultimately to a consistent inability to recover motile spermatozoa following freeze-drying. This paper reports the sequence of events in detail. Many of the events of importance achieved their significance only in retrospect, necessitating more of a reconstruction of unplanned events than the presentation of data from a series of organized experiments. EXPERIMENTAL PROCEDURE The procedure utilized for the drying of spermatozoa was identical to that developed for the freeze-drying of human erythrocytes (Meryman, 1960). The drying apparatus consisted simply of a large capacity gas-ballasted mechanical vacuum pump connected