MTT assay as a viability test of homograft valves

Abstract

Viability testing is important for all tissue valve banks due to the unproven long held concept that preimplantation viability of the homograft contributes to its durability in the recipient. At our Institute viability testing of 104 homograft valves, collected at autopsy, was done using the MTT assay. The valves were found to be viable by methyl thiazole tetrazolium (MTT) assay when the Warm Ischemic Times was less than eleven hours. After antibiotic treatment, at the most 30% of the valves were found to be viable by the MTT assay at twentyfour and fortyeight hours. Change in the storage medium from Hanks Balanced Salt Solution to Dulbeccos Modification of Eagle’s Medium did not change the time period for which viability was maintained. MTT assay is thus a simple, rapid and economical viability test well suited even for valves collected under unsterile conditions.