Spontaneously developed tail swellings (SDTS) influence the accuracy of the hypo-osmotic swelling test (HOS-test) in determining membrane integrity and viability of human spermatozoa.
OBJECTIVE
To investigate the prevalence of spontaneously developed tail swellings (SDTS) in human sperm samples that are commonly encountered in the laboratory, and their influence on the hypo-osmotic swelling test (HOS-test).


METHODS
Ejaculated, epididymal, and testicular sperm were evaluated for SDTS. Further, HOS-test scores were compared with those of vital stains using column washed sperm maintained in the laboratory.


RESULTS
SDTS, at <10%, was present in all types of sperm samples. The highest and lowest occurrences of SDTS were found in cryopreserved sperm, and column-washed sperm respectively. SDTS can inflate the HOS-test score, and so lower the accuracy of the HOS-test. However, the HOS-test efficiency can be improved by assessing SDTS in the sample.


CONCLUSIONS
HOS-test and vital stain cannot be used interchangeably in all circumstances for sperm viability determination. The accuracy of the HOS-test can be enhanced by incorporating SDTS as a correction factor.
Hossain
Amjad
A
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA. amhossai@utmb.edu
Osuamkpe
Collin
C
Hossain
Shaikat
S
Phelps
John Y
JY
D000328:Adult; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation; D006801:Humans; D007038:Hypotonic Solutions / Q000494:pharmacology; D008297:Male; D009997:Osmotic Pressure; D055101:Semen Analysis / Q000379:methods*; D012662:Semen Preservation; D013081:Sperm Motility / Q000187:drug effects; D053625:Sperm Retrieval; D013082:Sperm Tail / Q000648:ultrastructure*; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology
D007038:Hypotonic Solutions