Comparison of three wash techniques for the removal of microorganisms from semen

The objective of this study was to compare the effectiveness of three sperm separation techniques for producing samples free of seminal fluid microbes. Each of 11 semen samples were separated by the following techniques: wash, with centrifugation only; swim-up, with undiluted semen layered beneath medium; and wash and swim-up, with centrifuged sperm cells overlain with medium. Microbiology for both aerobic and anaerobic organisms of semen and washes was determined by standard methods. The microbes isolated from semen were similar to those found in previous reports. However, the swim-up technique proved more successful than either the wash or the wash and swim-up methods for the recovery of sterile spermatozoa (ten of 11 versus four of 11, P less than .05). It is recommended that the swim-up technique, with medium supplemented with penicillin and streptomycin, be used when preparing sperm samples for placement into the female reproductive tract.