Improved detection of allele loss in renal cell carcinomas after removal of leukocytes by immunologic selection.

We used immunologic selection to remove contaminating leukocytes from primary renal cell carcinomas and to improve detection of chromosome 3p allele loss. Leukocytes were removed from disaggregated renal cell carcinomas by a double-antibody, magnetic bead separation technique. Before immunologic selection, the preparations contained 26% +/- 15% (SD) tumor cells (n = 7); after immunologic selection, the preparations contained 76% +/- 12% tumor cells. The recovery of tumor cells in the purified preparations was about 10%. Detection of allele deletion was facilitated by immunologic selection. This method may be useful in allele deletion analysis of other human solid tumors that are contaminated with host leukocytes and, with appropriate modification, may be applied to tumors that are contaminated with other cell types.