Introduction: The importance of Sperm Viability Tests (SVT), in treatment of male infertility is evident. The most routine tests are E & N and HOST which are based on membrane permeability and integrity. Initially the aim of this study was to evaluate MTT assay as a sperm viability test based on mitochondrial activity. This test was designed not only for differentiation but also selection and separation of viable sperms from non- viable ones. Therefore this characteristic of sperm MTT viability assay makes it suitable for ICSI.
Materials and Methods: Washed sperm samples were incubated with MTT in different media and different times in order to obtain the best condition for carrying out Sperm MTT Viability Assay. Then coefficient of variation, of sperm MTT viability assay was obtained and sensitivity and specificity of each of mentioned tests were calculated. Then MTT, E & N and HOST were carried out simultaneously on 57 samples from infertile patient referring to Isfahan Fertility and Infertility Center. Then correlation coefficient of these tests with each other and also with sperm motility were obtained using SPSS software statistical program.
Since the characteristics of this test, make it suitable for ICSI, the effects of MTT positive sperms which injected into oocytes were studied on fertilization, cleavage and blastocyst formation. Human oocytes were divided into two groups? one group was injected with MTT positive sperms and the other one was taken as control.
Results: The optimal condition for sperm MTT viability assay were in Ham's F10 + 25 mM Hepes + 10% HAS at pH= 7.4 at 37oC for 2 hours. This assay showed a good significant correlation with HOST and E & N and sperm motility. All of the tests had high sensitivity but specificity of HOST was less that of E & N and MTT.
The results of the second stage show that there is no significant difference between the two groups of injected oocyte.
Conclusions: Sperm MTT viability assay appears to be suitable sperm viability test with sensitivity and specificity and low coefficient of variation. This test designed not only for differentiation but also selecting and separating viable sperms from non- viable ones. Therefore this characteristic makes sperm MTT viability assay suitable for ICSI. If it can be proven that MTT is not mitogenic or teratogenic, then sperm MTT viability assay might be useful for ICSI in patients with absolute or sever asthenospermia, especially in cases with tail abnormality.