The Combined Bisulfite Restriction Analysis (COBRA) Assay for the Analysis of Locus-Specific Changes in Methylation Patterns.DNA methylation is a heritable but reversible epigenetic mechanism of control over gene expression.  Here, we describe the combined bisulfite restriction analysis (COBRA) assay that allows analyzing the methylation status at a specific locus. 
COBRA
The protocol consists of the following major steps: bisulfite conversion of non-methylated cytosines to uracils, the locus-specific PCR amplification of converted DNA, restriction digestion, the analysis of restriction patterns on the gel, and the quantification of these restriction patterns using ImageJ or a similar program.
ImageJ