Researchers from Exact Sciences report in Clinical Chemistry on their quantitative allele-specific real-time target and signal amplification, or QuARTS, method. This approach includes "polymerase-based target amplification with an invasive cleavage-based signal amplification. The fluorescence signal is detected in a fashion similar to real-time PCR," the authors say. In their paper, the researchers describe using the approach to measure levels of methylated DNA extracted from colorectal cancer samples. "At a diagnostic specificity cutoff of 95 percent, methylated BMP3, NDRG4, VIM, and TFPI2 detected 84 percent, 92 percent, 86 percent, and 92 percent of colorectal cancers, and 68 percent, 76 percent, 76 percent, and 88 percent of adenomas, respectively," the authors write.

In a Clinical Chemistry article published online in advance, University of Virginia researchers led by James Landers describe their multiplex, PCR-based assay for determining warfarin-sensitivity genotypes. "The assay was developed with conventional PCR equipment and demonstrated for microfluidics infrared-mediated PCR. Genotypes were determined by [microchip gel electrophoresis] on the basis of the pattern of PCR products," the researchers say. Our sister publication PCR Insider has more on this work.

Finally, George Yousef from St. Michael's Hospital in Toronto writes in a new opinion piece that one of the challenges in implementing personalized medicine is the ability to extract helpful information from massive datasets. Yousef considers a strategy put forth by Michigan's Arul Chinnaiyan and his lab that combines whole-genome sequencing, whole-exome sequencing, and transcriptome sequencing of tumor and normal DNA to identify clinically relevant mutations. "Although the results are promising, the Michigan study highlights several existing challenges that need to be addressed, including certification of the technique, ethics approval, and the patient's informed consent," Yousef adds. "Cost remains a substantial challenge for scaling up the experiment; however, the cost is expected to decrease after the technique becomes approved for clinical practice."