Have you ever wondered why it takes so long to get laboratory test results? Molecular tests in particular often require days or even weeks-long turnaround times. Is this delay necessary? Will shorter turnaround times significantly benefit patient care? Carl Wittwer, MD, PhD, will address these questions during this morning’s plenary session, “Extreme Molecular Diagnostics.”
The Human Genome Project took 13 years to complete at a cost of about $2.7 billion. For the past 2 decades, scientists and researchers have been exerting great effort to make molecular tests faster and also be able to test multiple targets in a single reaction. These principles created fast and highly multiplexed polymerase chain reaction (PCR), digital PCR, and next-generation sequencing (NGS) assays. In some scenarios, testing turnaround times have dropped significantly to reach several minutes for simple molecular tests, less than an hour for complex syndromic panels, and less than a day for clinical genomics. Extreme molecular methods revolutionize this decreased analytical time to mere seconds.
PCR is a fundamental molecular diagnostic tool where it remains the base of most molecular techniques currently available. PCR run times have dropped to less than an hour from several hours when this method was introduced. In today’s plenary, Wittwer will explain how he was able to successfully perform PCR in seconds. He utilized instruments that cycle at extreme speeds and increased the rates of primer annealing and polymerase extension. He accomplished the latter by increasing primer and polymerase concentrations to match the cycling speed. Using this approach, the modified PCR reaction achieves efficient amplification with high sensitivity, specificity, and yield in less than 15 seconds. High-resolution melting analysis takes 4 seconds, allowing for extremely rapid sample-to-answer diagnostics.
Fast analysis has significant advantages for any application in which quick turnaround time is critical. While great advances have been made in point-of-care diagnostics in multiple clinical settings, the molecular space has comparatively lagged due to the complexity of molecular methods. Wittwer will explain how some diagnostics, particularly in infectious diseases, are time-sensitive since rapid therapeutic intervention—which depends on accurate diagnosis—is often crucial. Multiple cartridge-based systems for rapid infectious disease testing have been introduced that return results in an hour or less and can simultaneously test for a single or multiple pathogens. The random access feature of these systems enables resulting samples anytime without the need for batching. Molecular oncology laboratories recently introduced similar cartridge-based systems to provide rapid mutational analysis in cancer, thus complementing the more comprehensive NGS assays that take days or weeks to complete. Wittwer will emphasize that the value of point-of-care diagnostics must be focused on testing turnaround time. Extreme molecular diagnostics will make it possible for results to be readily available during initial patient visits.
Attendees at today’s plenary session will walk away clearly understanding the promise of extreme molecular diagnostics in while-you-wait infectious diseases, molecular oncology, and genetics. Though extreme PCR is not yet commercially available, Wittwer hopes that its demonstrated feasibility will encourage further work on implementing this breakthrough in practice, leading to better patient care and satisfaction.