….”and you should provide a negative PCR test for COVID”….
…”I’m negative in a chlamydia PCR test”…
This PCR abbreviation is ever present in our lives and in mine in particular as I am a doctor working in sexually transmitted infections. So, what is this PCR?
As far as I am concerned, it has been an invention that has rocked the scientific and medical world. With this technique we are able to detect genetic material from someone who was present at a crime scene, detect COVID, identify infections such as chlamydia and gonorrhea even when there are hardly any bacteria present (for example, when they are in the throat), identification of corpses, paternity test…. And this is all down to a little bacteria….
In the laboratory, if we would like to, say, look for chlamydia in a throat swab, the sample gets heated up. Then some strands of protein bind specifically (and only) to the DNA of the bacteria in question – chlamydia specific DNA in this example.
And then the PCR magic begins – the polymerase chain reaction – if the DNA strand we were searching for has been found, the PCR enzyme process starts making millions of copies of that DNA. The machine repeats the process over and over and the total DNA produced builds up. From just one strand of DNA more than a billion copies can be made.
In practice, this technique is so sensitive that it beats all of test hands down when it comes to gonorrhea or chlamydia detection, and also allows us to make a very early HIV diagnosis.
In my shop, you can find a test that detects 7 bacteria all at the same time in just one PCR test all from a urine sample.
And the HIV PCR test allows us to detect HIV just 10 days after a sexual contact.
Without PCR, it’s difficult to imagine how we would have managed the COVID pandemic
See below the amazing video that the DNA Learning Center have developed to show you what is going on inside a PCR machine.