Methylation-specific PCR of thep15^INK4b and p16^INK4agenes in selected plasma cells from patients with MGUS.

MS-PCR was performed with specific primers for unmethylated (U) and methylated (M) p15^INK4b and p16^INK4a alleles in Raji and RPMI-8226 cell lines as control and in CD138-selected MGUS plasma cells (samples 76, 77, 78, and 79). PCR product of appropriate molecular weight indicates the presence of unmethylated and/or methylated (A) p15^INK4b (162 bp and 154 bp for U and M, respectively) and (B) p16^INK4a alleles (154 bp and 145 bp for U and M, respectively) in that sample.