Overview :

Aoki et al correlated the ratio of protamine 1 to protamine 2 in sperm with its fertilization ability. This can help identify a group of men with impaired fertility. The authors are from the University of Utah in Salt Lake City.

Specimen: Semen collected 1:1 in TES and Tris (TEST) yolk cryoprecipitant

Parameters:

(1) protamine 1 concentration in ng per million sperm

(2) protamine 2 concentration in ng per million sperm

ratio of protamine 1 to protamine 2 =

= (concentration of protamine 1) / (protamine 2)

Interpretation:

• A normal ratio is 0.8 to 1.2.

• A reduced ratio was associated with reduced in vitro fertilization and a significantly reduced pregnancy rate.

• An increased ratio was associated with reduced in vitro fertilization.

Aoki VW, Liu L, Carrell DT. Identification and evaluation of a novel sperm protamine abnormality in a population of infertile males. Human Reproduction. 2005; 20: 1298-1306.

Aoki VW, Liu L, et al. Sperm protamine 1/protamin 2 raios are related to in vitro fertilization pregnancy rates and predictive of fertilization ability. Fertility and Sterility. 2006; 86: 1408-1415.