Principle

PRINCIPLE

  • The spermatozoa will have a plasma membrane as its outer covering. The integrity of plasma membrane varies between live and dead sperm.

This plasma membrane is intact in live sperms and its integrity is lost in dead sperms.

  • The live and dead sperm is assessed by a vital stain - eosin-nigrosin which was found by Hancock during 1951.

The eosin is a vital stain which can only pass through the loosely integrated plasma membrane of dead sperm and stains it as pink colour.
  • The stain will not pass through the live sperm and it appears as white in colour. The nigrosin is a negative stain which gives background colour.
  • Initially the live and dead sperm was assessed by Mayer et al. (1947) by using eosin (vital stain) and opal blue (background stain).
  • Later Hancock (1951) used eosin (vital stain) and nigrosin (background stain) and it is most commonly followed.
Last modified: Monday, 4 June 2012, 11:26 AM