Methylation-specific polymerase chain reaction (MSP) for SOCS1 (A) MSP for the unmethylated allele (U-MSP) and methylated allele (M-MSP), showing that with the MSP3′ primers, 6 normal peripheral bloods (N2, N4, N7, N8, N9, and N10) and 2 marrows (Ma1 and Ma3) showed methylation signals. MW indicates molecular weight control; B, blank; P, positive control of methylated DNA; U, U-MSP; M, M-MSP; N, normal peripheral blood; and Ma, normal marrow. (B) Sequencing of SOCS1 in 5 bisulfite-converted peripheral blood controls (N7 to N10 and Ma3) showing methylation signals with primer set MSP3′. The DNA sequence of the “methylated” (Me) PCR product was aligned and compared with the germ line sequence of the wild-type DNA (WT). Methylated cytosine residues in CpG dinucleotide remained as C, whereas unmethylated cytosine read as T after bisulfite conversion. Underlined N suggested hemizygous methylation in a CpG island. Note the presence of many TG islands, representing unmethylated CpG dinucleotides. (C) Sequencing of the methylated PCR product with the MSP3′ primers of the methylated positive control. (D) MSP for SOCS1 using the MSP5′ primers. None of the normal peripheral blood and marrow samples showed positive methylation signals. (E) Sequencing of the methylated PCR product with MSP5′ primers from the methylated control DNA, showing complete methylation.