HYPO-OSMOTIC SWELLING TEST

Reference: 

The hypo-osmotic swelling test is a sperm vitality test based on the principle that live spermatozoa swell due to the absorption of a hypo-osmotic solution. 
The HOS test is based on the test procedure described in the WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction (1999).

The HOS test has a shelf life of 12 months from date of produce.