Flow cytometric DNA analysis after immunoselection of bladder tumor cells with monoclonal antibody DU83.21

Adequate preservation of neoplastic cells and the elimination of interference by inflammatory cells in measuring tumor cell DNA content represent two important objectives necessary for accurate flow cytometric analysis of bladder carcinomas. An experimental model consisting of a mixture of cultured bladder carcinoma cells (T24) and human buffy-coat (BC) cells was used to evaluate various preservatives and an anti-bladder carcinoma monoclonal antibody (MoAb), DU83.21, for separating inflammatory cells (BC cells) from T24 cells. A final concentration of 25% ethanol was found to be the most effective preservative of several tested. After incubation with the MoAb DU83.21 and propidium iodide (DNA stain), the T24 cells could be separated from the BC cells, permitting accurate DNA analysis of the tumor cells. Application of this system to specimens from bladder cancer patients enhanced the detection and DNA analysis of the tumor cell populations.