Sperm motility test
The eosin test ascertains sperm motility. Dead sperm cells with holes in the membranes absorb the eosin and appear pinking while, normal live sperm with intact sperm will remain without the stain. Secondly, a hypo-osmotic swelling test is also used but to a lesser degree. The semen, in this case, is diluted in a hypoosmotic solution so that it enters the sperm cell. A sperm that is alive shows a tail as the solution enters the cell, while a dead sperm will not.
Results of the eosin stain test
The eosin test should not result in a score of less than 58% alive sperm cells. However, a percentage under 58% may still qualify an individual for an ICSI procedure.