Figure 3

Frequency of gene methylation in colorectal neoplasia. Methylation levels of individual genes (left hand labels) were determined by qMSP using primer pairs and conditions described in Additional file 2: Table S4. The percentage of samples showing greater than 10% methylation is shown for CRC (red spots), matched normal tissue (green) and adenomas (purple). Up to 78 cancer samples were tested for any individual gene. The size of the spots is proportional to a log2 transformation of the number of samples tested (small gray circle10; medium gray circle 40; large gray circle 80). The difference in detection cycle between CpGenome™ DNA and wbc DNA (ΔCt ) is presented as bars to the right with lengths proportional to the ΔCt value (which is also presented numerically within each bar). An asterix denotes the qMSP reaction completed before reaction products from wbc DNA were detected, so the ΔCt is at least this value.