Advantages of Digital qPCR
Reginald Beer, a principal investigator and associate program leader at Lawrence Livermore National Laboratory, will discuss the advantages of digital qPCR at the meeting, as well as the potential for ultra-fast qPCR. Beer was reportedly the first to demonstrate real-time, droplet-based digital qPCR on a chip in 2007, and he also has developed an instrument capable of detecting both DNA and RNA targets in picoliter droplets.
Beer notes that digital qPCR involves partitioning targets in such a way that there is either one copy or no copies of the target in each PCR well. This offers significant advantages in absolute quantification as a result of the high accuracy in knowing the starting concentration of template due to Poisson statistics. The technology is complex compared to bulk PCR, however, and it is not appropriate for all qPCR applications, he reports.
Digital qPCR is ideal for low-copy number detection in a sample with a high concentration of interfering templates, such as applications involving rare mutation detection, absolute quantitation, copy-number variation, and haplotyping. Advances that Beer sees coming in digital qPCR include instrument and process simplification and higher throughput.
Emphasizing his belief that “speed will serve the broad scientific community,” Beer also touts his team’s recent work developing an ultra-fast PCR instrument that can complete 30 PCR cycles in under three minutes. Such an instrument would have numerous benefits, including higher throughput, faster results for clinical applications, and widespread utility in forensics and food safety.
The device reportedly achieves extremely fast thermal cycling, making possible heating and cooling rates of 45°C per second. “We were really encouraged by the fact that off-the-shelf polymerases worked at these speeds, and there are a lot of parameters that can be adjusted to potentially go even faster.” Dr. Beer and his team are currently working to develop an optical detector for an ultra-fast qPCR instrument.