Bisulfite sequencing of CD44 exon 1 region. The CpG island of CD44 is located between-638 and +496 relative to the ATG codon, thereby spanning the whole exon 1. The CD44 exon 1 region (682 bp, 53 CpG sites) was sequenced after bisulfite conversion of DNA from cell line EB-1 (BL) and cell line REC-1 (MCL) as well as from patient samples BL23 (BL), DLBCL1 (DLBCL) and MCL2 (MCL) and tonsil DNA from a healthy donor. Each line depicts a sequenced clone representing the methylation status of an individual allele. CpGs are represented as open dots (if unmethylated) or filled dots (if methylated). In BL cell line EB-1 and in the BL patient clones with dense CpG methylation were detected, the DLBCL patient showed partial CpG methylation next to the ATG codon. In contrast no methylation of these sites was detectable in the MCL cell line REC-1, the MCL patient and normal tonsil DNA. Bisulfite sequencing confirmed results of CD44 methylation status detected with MS-MLPA and MSP. Note that CpG sites analyzed by the MS-MLPA probe (green) and MSP primers (red) are not identical.