The effect of a two-hour, room temperature incubation of human spermatozoa in TEST-yolk buffer on the rate of fertilization in vitro

J Assist Reprod Genet. 2004 May;21(5):169-73. doi: 10.1023/b:jarg.0000031250.35595.ed.


Purpose: To reassess the use of TEST-yolk buffer (TYB) in an in vitro fertilization (IVF) program by comparing fertilization rates achieved in a glucose-free cleavage medium by the standard IVF preparation of sperm versus a 2-h, room temperature incubation of sperm in TYB.

Methods: Oocytes collected for IVF were randomly split into two groups and inseminated with either TYB-treated sperm or IVF-prepared sperm.

Setting: Stanford Reproductive Endocrinology and Infertility Center.

Patients: Fifty couples undergoing IVF with at least 10 mature oocytes.

Main outcome measures: Fertilization rates in vitro.

Results: Fertilization rates were significantly higher (p = 0.015) with TYB treatment. The average 2PN fertilization rate was 49.6% (188/379) for the IVF group and 57.4% (221/385) in the IVF with TYB group.

Conclusions: A 2-h, room temperature incubation of sperm in TYB produces significantly higher 2PN fertilization rates as compared to standard IVF preparation of sperm in a current generation cleavage medium.

MeSH terms

  • Culture Media / pharmacology
  • Female
  • Fertilization
  • Fertilization in Vitro / methods*
  • Glucose / chemistry*
  • Glucose / metabolism
  • Humans
  • Male
  • Oocytes / metabolism
  • Pregnancy
  • Pregnancy Outcome
  • ROC Curve
  • Sensitivity and Specificity
  • Spermatozoa / cytology*
  • Spermatozoa / metabolism
  • Temperature
  • Time Factors
  • Tromethamine / chemistry*


  • Culture Media
  • TES-Tris yolk buffer
  • Tromethamine
  • Glucose