Ml. Check et al., IMPROVED RESULTS OF THAWED SPERM CRYOPRESERVED WITH SLOW STAGE - COOLING WITH A CELLEVATOR, Archives of andrology, 37(1), 1996, pp. 61-64
There is a need to develop a sperm cryopreservation technique that wil
l allow good pregnancy rates following intrauterine insemination of th
awed semen specimens that have been frozen prior to sperm-destructive
procedures, such as surgery, chemotherapy, or radiation therapy. A slo
wer cooling rate using a commercial semiprogrammable freezer may provi
de improved post-thaw motility and hypoosmotic swelling (HOS) test sco
res. However, the cost of this apparatus precludes it from being used
in most andrology centers. This study compares the efficacy of slow st
age cooling using an inexpensive cellevator (a device used to freeze l
ymphocytes) to liquid nitrogen vapor freezing. The semen from 27 males
was equally divided and one aliquot was cryopreserved with the cellev
ator stage cooling and the other with the liquid nitrogen vapor techni
que. The percent motility and percent grade A sperm post-thaw were sig
nificantly higher when cryopreserved with the cellevator than with vap
or freezing, as was the mean percentage of sperm showing HOS changes.