High-resolution melting analysis

High-resolution melting analysis (HRM or HRMA) is a highly sensitive, post-PCR method used primarily for the detection of mutations, polymorphisms, and epigenetic differences in double-stranded DNA samples. It has become an invaluable tool in molecular biology and genetic testing due to its simplicity, efficiency, and cost-effectiveness. HRM analysis relies on the precise monitoring of the melting (denaturation) behavior of PCR-amplified DNA fragments in the presence of saturating dyes that fluoresce in the presence of double-stranded DNA. As the DNA melts, the fluorescence decreases, and the melting temperature (Tm) can be determined. Differences in the DNA sequence among samples result in distinct melting profiles, allowing for the differentiation of even single nucleotide polymorphisms (SNPs).

Principle

The principle behind HRM analysis is based on the observation that the DNA melting temperature is highly dependent on its nucleotide composition, length, and GC content. During HRM, the PCR product is slowly heated, and the decrease in fluorescence is measured in real-time. This generates a melting curve that can be analyzed to detect variations in the DNA sequence. The presence of a mutation or polymorphism alters the melting curve, which can be detected by comparing it to a reference curve obtained from known sequences.

Applications

HRM analysis is used in a wide range of applications including:

• Genotyping and mutation screening in genetic research
• Detection of somatic mutations in cancer research
• Identification of pathogens in infectious diseases
• Analysis of epigenetic changes, such as DNA methylation
• Pharmacogenomics and personalized medicine

Advantages

HRM analysis offers several advantages over other genotyping methods:

• High sensitivity and specificity for detecting variants
• No requirement for post-PCR processing, which reduces the risk of contamination
• Cost-effective as it eliminates the need for expensive probes or dyes
• Rapid and high-throughput capability
• Ability to analyze small DNA fragments

Limitations

Despite its advantages, HRM analysis has some limitations:

• Difficulty in distinguishing between very similar melting profiles, which may require additional analysis
• Limited by the quality and quantity of the input DNA
• Interpretation of results can be complex and requires specialized software

Procedure

The HRM analysis procedure involves several steps: 1. DNA extraction and purification from the sample of interest 2. PCR amplification of the target DNA region using specific primers 3. Mixing of the PCR product with a high-affinity DNA binding dye 4. Gradual heating of the mixture to denature the DNA, while continuously measuring the fluorescence 5. Analysis of the melting curves to identify variations in the DNA sequence

Conclusion

High-resolution melting analysis is a powerful technique for the rapid and cost-effective detection of genetic variations. Its application spans various fields of biology and medicine, facilitating advancements in research, diagnostics, and personalized medicine. Despite its limitations, HRM remains a preferred choice for many researchers and clinicians for genotyping and mutation screening.

High-resolution melting analysis Resources
Latest articles Most recent articles Ongoing trials	Wikipedia