Viability status before and after treatment with antibiotics was investigated in a total of 104 homograft valves using MTT (3-[4, 5-dimethyl thiazol-2-y1]-2, 5-diphenyl tetrazolium bromide). The valves with warm ischaemic time above 11 hours, were found to be non-viable. Increase in storage time directly decreases cell viability. Methyl thiazol tetrazolium (MTT) assay can be used as a reliable, simple, rapid and economic method for assessing the viability status based on mitochondrial respiration even for homograft valves. Basal media with and without nutrients i.e., DMEM and Hanks BSS showed no difference in viability of the cells.