Why PCR need to be reinvented?
Because it can not multiplex, of course! (Or should we learn from Clinton and say, “it is the multiplexing, stupid!”)
When PCR was invented some 20 years ago, it can only amplify one target at a time. And it remain so for so many years. People tried to do multiplex PCR, but it is difficult. For 2-3 targets, it is fine, but more than 3, it become increasingly impossible.
Why we need multiplex? Because many of the diseases, as we know it, are defined by symptoms. By sharing symptoms, diseases appears identical to physician’s eyes even though the etiology is totally different. And symptoms are what we call genotypes. They are results, not causes. The cause is usually associated with some genetic material changes: mutation in our own DNA, or introducing DNA into our system (infections). And more than often, we many causes can generate the same results, i.e., different genetic changes leads to the same clinical symptoms. For example, coughing and fever are common respiratory symptoms, but this clinical presentation may be associated with as many as 30 different pathogen infections, different bacteria and viruses can lead to the same symptoms. Therefore, we need a multiplex test that can study all possible infections with one assay, from one test run, in one machine, with one procedure, and from one sample.
Without multiplexing, PCR’s application in clinical diagnosis is limited, because in order to provide clinical value, a molecular differential diagnosis is required.
It amazes me that not many people know there is a problem! (of doing multiplex PCR). When I submitted the first paper about multiplex PCR (then, tem-PCR), one of the reviewer’s comment was: “multiplex PCR is not difficult and many products are available on the market.” Is he from this planet?
People who do not know problems will never solve one, and those do not have a headache associated with a problem will never invent a solution.
That is OK, more fun for us.
Step one for innovation is to recognize the problem.
* Disclaimer*
Although we may use the words “Diagnosis” or “Diagnostics” in this blog, our products are NOT FDA approved for such uses. We are developing technologies that may eventually have clinical applications, but for now, all our products are for research use only.