IMMUNOBEAD-PCR - A TECHNIQUE FOR THE DETECTION OF CIRCULATING TUMOR-CELLS USING IMMUNOMAGNETIC BEADS AND THE POLYMERASE CHAIN-REACTION

The presence of tumor cells in the circulation may predict disease rec urrence and metastases. We have developed a sensitive technique for th e detection of carcinoma cells in blood, using immunomagnetic beads to enrich for epithelial cells and the polymerase chain reaction to iden tify a tumor marker. The colon carcinoma cell line SW480, homozygous f or a K-ras codon 12 mutation, was used to establish optimal conditions . The SW480 cells were serially diluted in normal blood and incubated with immunomagnetic beads labeled with a monoclonal antibody specific for epithelial cells. Cells bound to the beads were retrieved using a magnetic field and the presence of K-ras codon 12 mutations determined by a polymerase chain reaction based analysis. SW480 cells could be d etected in dilutions up to 1 SW480 cell/10(5) leukocytes in whole bloo d.