title: Swim-down: a rapid and easy method to select motile spermatozoa.
abstract: A method is developed to improve the quality and the number of sperm recovered after laboratory processing, consisting of a swim-down technique. This study was designed to compare quality sperm after selection with a swim-up and a swim-down method. Fifty-nine men, 23-52 years of age, with a period of infertility of 1 to 14 years were included in the study. The efficacy of the swim-down technique as compared to the swim-up technique was assessed by measuring percentage of sperm recovery, sperm motility, the hypoosmotic swelling test, acrosome reaction, and the sperm penetration to zona-free hamster oocyte assay. The swim-down procedure using pure serum as culture medium showed a higher percentage (p < .02) of spermatozoa with forward progression and a higher number of recovered (p < .05) spermatozoa than the swim-up technique. The fertilizability was similar with both methods. The swim-down procedure using pure serum could be useful for intrauterine insemination where a higher number of spermatozoa is required.
authors.affiliation: Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: G F
authors.initials: GF
authors.lastname: Gonzales
authors.forename: R E
authors.initials: RE
authors.lastname: Pella
mesh_terms: D000328:Adult; D002469:Cell Separation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology