ISOLATION OF BONE-MARROW PLASMA-CELLS BY NEGATIVE SELECTION WITH IMMUNOMAGNETIC BEADS

In order to isolate bone marrow plasma cells from patients presenting with multiple myeloma or monoclonal gammopathy of undetermined signifi cance, we developed a method for purifying these cells by negative sel ection using monoclonal antibodies and immunomagnetic beads. The resul ts presented here were obtained from 75 procedures. Purity was extreme ly variable (20-100%) and was dependent on the percentage of plasma ce lls in the original bone marrow sample with a 10% cut-off, beyond whic h purity was over 96% in all cases. The mean yield was about 20%. The cells collected were viable and suitable for immunophenotyping, semi-q uantitative studies of oncoproteins, and PCR.