Use of the MTT assay for rapid determination of chemosensitivity of human leukemic blast cells.

A microcytotoxicity assay employing a tetrazolium salt has been adapted for testing the response of human leukemic blast cells to a variety of chemotherapeutic agents. After exposure to various concentrations of drugs, the viability of fresh leukemic blast cells was measured using a tetrazolium salt, MTT, which is converted to blue formazan crystals by living cells. The amount of formazan produced was quantitated using a microtitre plate spectrophotometer. In the present study, optimal conditions for chemosensitivity testing of human leukemia samples were determined, and the relative chemosensitivity of five patient samples was tested.