In situ RT-PCR on BM plasma cells with patient-specific primers. (A) Plasma cells sorted from a BM of MM patient 10 and a healthy donor underwent in situ amplification with patient 10 CDR2/CDR3-IgH–specific primers. (B) Plasma cells sorted from a BM of MM patient 2 and a healthy donor underwent in situ amplification with patient 2 CDR2/CDR3-IgH–specific primers. (C) Plasma cells sorted from a BM of MM patient 11 and a healthy donor underwent in situ amplification with patient 11 CDR2/CDR3-IgH–specific primers.