The present invention provides new and improved assay for detection of genomic methylated CpG islands. This new method is termed the methylated-CpG island recovery assay (MIRA). In accordance with one embodiment, MIRA comprises the steps of: (a) incubating genomic DNA fragments with a methylated CpG island binding protein in the presence of a binding partner for the binding protein to produce bound DNA containing methylated CpG islands, (b) isolating the bound DNA, and (c) detecting CpG island methylation by gene-specific amplification reactions. In accordance with a preferred embodiment, MIRA comprises the steps of: (a) incubating sonicated genomic DNA with a matrix containing a fusion protein of glutathione S-transferase (GST) and MBD2b (GST-MBD2b) in the presence of MBD3L1 to produce bound DNA containing methylated CpG islands, (b) eluting bound DNA from the matrix, and (c) detecting CpG island methylation by gene-specific amplification reactions.