Patent ID: 8026079

Claim:
A method for detecting live cells, injured cells and dead cells of a microorganism in a test sample by flow cytometry, which comprises the following steps: a) treating the test sample with an enzyme having an activity of decomposing cells other than those of the microorganism, colloidal particles of proteins or lipids existing in the test sample, b) treating the test sample with a topoisomerase poison selected from the group consisting of amsacrine, camptothecin, doxorubicin, ellipticine, etoposide, mitoxantrone, saintopin, topotecan and CP-115,953 and/or a DNA gyrase poison selected from the group consisting of ciprofloxacin, ofloxacin, enoxacin, pefloxacin, fleroxacin, norfloxacin, nalidixic acid, oxolinic acid and piromidic acid, c) treating the test sample treated in the steps a) and b) with a first stain agent and a second stain agent, wherein the first stain agent stains live cells in different color from injured cells and dead cells, and the second stain agent stains live cells and injured cells in different color from dead cells, and d) detecting the live cells, injured cells and dead cells of the microorganism in the test sample treated with the first stain agent and second stain agent by flow cytometry.