MSP of DAP-Kinase. Primer sets used for amplification are designated as unmethylated (U) or methylated (M). The size of the MSP product for the unmethylated reaction is 106 bp. The size of the MSP product for the methylated reaction is 98 bp. In all MSP reactions, 10λ of product was run on a 6% polyacrylamide gel, stained with ethidium bromide, and visualized under UV illumination. (A) MSP analysis of DNA from lymphocytes of 6 normal individuals shows amplification of only unmethylated alleles in the DAP-Kinase CpG island. (B) MSP of DAP-Kinase in lymphoblastoid cell lines (cell lines immortalized by EBV-transformation) shows amplification of only unmethylated alleles in the DAP-Kinase CpG island. (C) MSP of DAP-Kinase in cell lines. Raji shows amplification of only methylated alleles for the DAP-Kinase CpG island. U937, an expressing cell line, shows amplification of only unmethylated alleles for the DAP-Kinase CpG island. (D) MSP of DAP-Kinase in Burkitt’s lymphoma samples. Each sample shows aberrant methylation of the DAP-Kinase CpG island. None of these samples was microdissected, so the unmethylated alleles amplified in each sample represent either normal tissue found within the tumor samples or heterogeneity of aberrant methylation within the tumor sample itself. (E) MSP of DAP-Kinase in lymphoma samples. Samples: B, B-cell non-Hodgkin’s lymphoma; T, T-cell non-Hodgkin’s lymphoma; H, Hodgkin’s lymphoma. The majority of the B-cell non-Hodgkin’s lymphoma samples show aberrant methylation of the DAP-Kinase CpG island, and none of the T-cell non-Hodgkin’s lymphoma samples do.