A non isotopic method for the measurement of cell membrane integrity

In vitro cytotoxic assays often use various technical approaches for the measurement of cell mortality. Assays such as trypan blue exclusion or chromium release measure cell membrane integrity but they are either time consuming, not sensitive enough or they generate radioactive wastes. We have developed a dehydrogenase release assay which takes advantage of a new fluorescent amplification system. Mouse L929 fibroblasts and tumor necrosis factor (TNF-alpha) were used as a model system. This approach is sensitive, rapid, reproducible and may be used advantageously for mixed lymphocyte reaction (MLR). This new economical assay may be easily automated for large scale cytotoxicity testing using cell membrane integrity.