title: The microsperm penetration assay: development of a sperm penetration assay suitable for oligospermic males.
abstract: OBJECTIVE
  To develop a specialized sperm penetration assay (SPA) for the evaluation of sperm from oligospermic patients.
  
  
  METHODS
  The development of the assay is in four parts: determine optimal sperm number; demonstrate quality control; establish statistical limits for fertile population; compare results to in vitro fertilization (IVF) outcome.
  
  
  METHODS
  A group of 63 patients with oligospermia and/or poor motility and a group of 17 fertile donors were compared using the optimized SPA and the micro-SPA. Sperm from a third group of 35 patients were simultaneously incubated with human ova (IVF) and hamster ova (micro-SPA).
  
  
  METHODS
  Both types of SPA scores are expressed as a sperm capacitation index (penetrations per ovum). Outcome of IVF is expressed as a percent of ova fertilized.
  
  
  RESULTS
  Using 25,000 sperm was found to be optimal. The normal fertile range was statistically determined to have a lower limit (-2 SD) of 2.0 penetrations per ovum. When scores from 63 male factor patients were compared using the optimized SPA, only 43% had sufficient swim-up sperm. However, the micro-SPA could accurately test 100% of the samples because it requires only one tenth the number of sperm.
  
  
  CONCLUSIONS
  The micro-SPA provides a valuable diagnostic test for the evaluation of the male factor patient.
authors.affiliation: Scott Department of Urology, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: A
authors.initials: A
authors.lastname: Johnson
authors.forename: R G
authors.initials: RG
authors.lastname: Smith
authors.forename: B
authors.initials: B
authors.lastname: Bassham
authors.forename: L I
authors.initials: LI
authors.lastname: Lipshultz
authors.forename: D J
authors.initials: DJ
authors.lastname: Lamb
mesh_terms: D000818:Animals; D006224:Cricetinae; D005188:False Negative Reactions; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D008647:Mesocricetus; D009845:Oligospermia / Q000175:diagnosis*; D011786:Quality Control; D012680:Sensitivity and Specificity; D013076:Sperm Count; D013084:Sperm-Ovum Interactions