DNA testing represents a revolution postponed, perhaps, but one that is now clearly under way. After years of glowing predictions that didn’t immediately translate into change in clinical diagnostics, DNA testing has emerged fully from research into clinical practice, and is now one of the fastest growing segments of the diagnostics market.
Molecular tests are now used to diagnose disease and disease susceptibility, in prenatal genetic assessments, in tissue typing for organ transplantation, and to screen for inherited diseases.
Instrumentation now automates many of the sample-preparation and assay steps that were formerly labor-intensive. New tests are being launched all the time and many more are in development. The result is that molecular testing is now used in many areas of healthcare including: cardiology, oncology, infectious diseases, and inherited diseases and disorders.
The contribution that these tests can make to patient outcome, however, faces significant barriers including reimbursement issues, lack of standardization across test platforms, limited quality-control products and programs, and the inability to fully interpret test data.
Roche’s PCR technology has dominated molecular testing since the mid 1980s. As a matter of economics and, at other times, a matter of scientific pride and innovation, some scientists and companies have looked for ways to avoid paying PCR license fees to Roche. The result is that a myriad of other DNA amplification and molecular test platforms have been introduced, but none have managed to displace PCR.
Another driver for technological innovation in molecular testing is the need to design technologies that can be easily miniaturized and simplified for use in routine laboratories that have not yet invested in molecular methods.
The technologies that most comply with these testing requirements include bead arrays, electrochemical arrays, and microarrays. Many of these technologies are poised to overtake PCR sometime in the future and for some applications. But for now, Roche Diagnostics and PCR still account for the lion’s share of the molecular test market.
Increasing market penetration of molecular assays in the next few years is in part due to maturation of the technology itself and the development of appropriate diagnostic applications. The further success of these assays will, for the most part, result from the commercialization of rapid, user-friendly and economical high-quality testing systems and the discovery of molecular-based therapeutics that will allow for more individualization of disease management.
To date this promise has yet to be fulfilled. Although a range of companies have fairly user-friendly systems, the bulk of molecular testing is still performed with in-lab developed tests and test services. Rapid point-of-care devices for infectious diseases have already been commercialized, however, none are available for nucleic acid testing.
Molecular medicine will ultimately transform the entire spectrum of disease management, from assuring the early detection of disease, to defining the prognosis of disease evolution and predicting a patient’s response to specific therapies.
The application of molecular technologies to clinical analyses has received widespread attention. These tests have already made their mark in diagnostic systems and will continue to make further inroads in the next five years. Key issues that will impact on the market success of molecular tests include:
- Significant changes in healthcare delivery that will herald a new era in diagnostic testing needs. This new era requires sophisticated, sensitive assays that are user-friendly and cost effective. This bodes well for miniaturized molecular test platforms
- Demand for faster test turnaround time from sample collection to results availability.
- Customers also want a large menu of tests available on a single platform since molecular tests must account for variability in test targets. These tests must have high sensitivity for analytes in small concentrations, be quantitative, and must use small whole blood, urine, saliva, and CSF samples.
- Finally test systems must also be easy to use. This is crucial for the growing use of diagnostic assays in point-of-care settings.