Release of lactate dehydrogenase (LDH) into cell culture medium is often used to assess cell death. As the cell membrane integrity breaks down, the enzyme is released and can then be quantified. However, the stability of LDH within cells can also be used to determine cell viability in whole sections of fresh tissue (16). As LDH is stable for 36–48 h after cell death (17), tissue sections can be prepared and the cell viability analysed even though the cell does not need to be viable at the time of assay. In conclusion, the optimal viability assay depends on the cell type, culture conditions applied, and the specific questions being asked. When detailed information is required it may be more suitable to apply more than one method in order to confirm the results of individual assays.