Methylation-specific PCR (MSP) is an analysis method of DNA methylation patterns in CpG islands. CpG islands are important in the regulation of gene expression. Excessive methylation of CpG dinucleotides in promoter represses the gene expression.
MSP looks at the overall methylation status of a sample. PCR primers are specific for methylated cytosines so only methylated DNA will be amplified. The ability of MSP to differentiate methylated from unmethylated cytosine is dependent upon sodium bisulfite treatment of DNA which retains the methylation marks of cytosines together with the specific amplification of this modified DNA using primer sets complimentary only to the formerly methylated or unmethylated alleles.15
MSP Steps:15
- Sample preparation—can be used for a variety of samples including body fluids and paraffin-embedded samples
- Treatment of genomic DNA with sodium bisulfite
- Methylation-specific PCR using specific primer sets, one (primer M) that binds specifically to the methylated sequence and the other (primer U) that only binds to the unmethylated sequence
- If primer M can be used to amplify the fragment, the detected site is methylated. If primer U can amplify the fragment, then there is no methylation at the detected site.
- PCR data analysis
