DNA Methylation Analysis
DNA Methylation Analysis

DNA methylation is an epigenetic event that affects cell function by altering gene expression and refers to the covalent addition of a methyl group, catalyzed by DNA methyltransferase (DNMT), to the 5-carbon of cytosine in a CpG dinucleotide.

Our staff works hard to make the DNA Identity Testing Center your choice of provider for all DNA testing services. We ensure superior quality, service and convenience to our clients. In our commitment to providing convenience, please know that we provide a free DNASwabTM Home DNA Collection Kit for use in all types of private DNA tests.

Methods for DNA Methylation Analysis
Methods for DNA Methylation Analysis
Methods for DNA methylation analysis can be divided roughly into two types: global and gene-specific methylation analysis.For global methylation analysis, there are methods which measure the overall level of methyl cytosines in genome such as chromatographic methods and methyl accepting capacity assay.For gene-specific methylation analysis, a large number of techniques have been developed. Most early studies used methylation sensitive restriction enzymes to digest DNA followed by Southern detection or PCR amplification.DNA Identity Testing Center.
Methylation-Sensitive Single-Nucleotide Primer Extension
The methylation-sensitive single-nucleotide primer extension (Ms-SNuPE) method incorporates amplification of bisulfite-treated DNA, followed by a quantification of the ratio of methylated versus unmethylated cytosines at CpG sites (6). This is accomplished by incubating the PCR product with internal primers that anneal to the PCR template and terminate immediately 5' of the cytosine to be assayed.
Combined Bisulfite Restriction Analysis
An alternative method, called combined bisulfite restriction analysis (COBRA), uses standard sodium bisulfite PCR treatment followed by restriction digestion and band quantification (7). The primers used in the PCR do not span CpG dinucleotides so that the amplification step does not discriminate between templates according to their original methylation status. Instead, restriction enzymes are used to indicate methylation, based on the creation of new or retention of pre-existing restriction sites after bisulfite modification.
Bisulfite-PCR-SSCP
Bisulfite-PCR-SSCP
A more widespread procedure combines a bisulfite treatment and PCR-single-strand conformation polymorphism analysis (Bisulfite-PCR-SSCP or BiPS) (8). In a first step, the converted DNA is amplified with primers that have no CpG sites in the corresponding region of the original DNA, and as such amplify both unmethylated and methylated DNA.
Methylation-Specific PCR
The fourth and most popular method is methylation-specific PCR (9). It is a breakthrough in speed and sensitivity for gene methylation analysis. After bisulfite conversion, PCR is performed using primers that distinguish methylated from unmethylated DNA. Unlike the procedures using restriction enzymes, MSP can be used to analyse any specific CpG site by appropriate primer design and it is not prone to false-positive results.
  All Rights Reserved By 800DNAEXAM.com © 2008 Designed by Segnant