Patent ID: 7910296

Claim:
A method of calculating the relative methylation density for a target locus in a DNA sample, the method comprising, i. contacting a first portion of the DNA sample with McrBC under partial digestion conditions where the resulting number of remaining intact copies of the locus is inversely proportional to the quantity of methylation at the locus; ii. quantitatively amplifying intact copies of the locus in the DNA sample after step i; iii. identifying a cycle-threshold (Ct) value from step ii; iv. quantitatively amplifying intact copies of the locus in a second portion of the genomic DNA that has not been cut by a restriction enzyme; v. identifying a cycle-threshold (Ct) value from step iv; and, vi. determining the relative methylation density for the target locus by calculating the difference (ΔCt) between the Ct from step iii and the Ct from step v, wherein 2 |ΔCt| is proportional to the relative methylation density.