A: Fully methylated and unmethylated DNA were mixed (0%, 25%, 50%, 75%, 100%) and hybridized to microarray. The Cy3 green and Cy5 red fluorescence signals of MLH1, TERT and MGMT promoter region are shown, reflecting the indicated percentage of methylation. From top to bottom, the five probes are positive control (1), negative (2), MLH1 (3), TERT (4) and MGMT (5). B: Three calibration curves for measuring methylation densities in MLH1, TERT and MGMT promoter region. The intensity ratios (Y-axis) represent signal intensities of (Cy5sam*Cy3pos)/(Cy5pos*Cy3sam).
Zhang et al. BMC Genomics 2008 9:59 doi:10.1186/1471-2164-9-59