When it comes to genotyping and mutation scanning, high-resolution DNA melting is emerging as the technique of choice because it is inexpensive simple, accurate and rapid.  Development of this method of DNA analysis has been underway since its introduction in 2002 by a team of researchers from our Pathology Department led by Dr. Carl Wittwer and Dr. Karl Voelkerding at the University of Utah coupled with collaborative efforts from Idaho Technology. 

High-resolution melting required new instrumentation.  The first high-resolution instrument developed, named the HR-1, remains the most accurate with the fastest analysis speed, while the LightScanner has the highest throughput. 

In addition to the special instrumentation, high-resolution melting uses special saturation dyes that fluoresce only in the presence of double stranded DNA.  These dyes are included in the PCR amplification process.  When the sample is heated to high temperatures, the DNA denatures and the fluorescent color fades away as the double stranded DNA separates, generating a melting curve. Because different genetic sequences melt at slightly different rates, they can be viewed, compared, and detected using these curves.  Even a single base change will cause differences in the melting curve.  The process can be used for specific genotyping, comparing sequence identity between two DNA samples, and scanning for any sequence variant between two primers.

High-resolution DNA melting is becoming more popular as its accuracy and simplicity is recognized.  High-res DNA melting makes it possible to quickly and accurately determine whether DNA sequences match, providing an interesting option for transplantation matching and forensics.

Genotyping via high-resolution melting is more streamlined and less expensive than methods that use complex probes.  No processing is required, and when combined with the speed of rapid-cylce PCR, has interesting potential for personal DNA diagnostics.  For example, the amount of medication a person needs is often dependent on sequence variants in genes that can be determined through high-resolution DNA melting. 

Hi-res melting can also be used to scan large genes for variation, in many cases greatly reducing or eliminating the need for sequencing.

Although high-resolution DNA melting is relatively new, it is expanding and being improved upon by our talented team of scientists in Pathology and we are excited to be at the forefront of such innovative and important technology. 

More information at www.dna.utah.edu

References:

1.  Reed GH, Kent JO, Wittwer CT. High-resolution DNA melting analysis for simple and efficient molecular diagnostics. Pharmacogenomics. 2007 Jun;8(6):597-608.

2: Herrmann MG, Durtschi JD, Wittwer CT, Voelkerding KV. Expanded Instrument Comparison of Amplicon DNA Melting Analysis for Mutation Scanning and Genotyping. Clin Chem. 2007 Jun 7; [Epub ahead of print]

3: Vandersteen JG, Bayrak-Toydemir P, Palais RA, Wittwer CT. Identifying common genetic variants by high-resolution melting. Clin Chem. 2007 Jul;53(7):1191-8.

4: Montgomery J, Wittwer CT, Palais R, Zhou L. Simultaneous mutation scanning and genotyping by high-resolution DNA melting analysis. Nat Protoc. 2007;2(1):59-66.