Celebrating how quickly science becomes everyday routine

DNA background

DNA background - Credit: Getty Images/iStockphoto

Occasionally I am discombobulated. Not only do some of the scientific developments leave me speechless but the speed of development from an obscure piece of geeky research to becoming a part of everyday life is discombobulating.

In the 1970s, I went to a lecture where they presented an amazing science fiction scanning machine called an NMR. The name was changed to MRI scans and now they are just another routine investigation.

As a student I was shown an ultrasound test used to look at unborn babies.

To me it just looked like an out of focus black and white photo but the expert pointed out the baby’s head and body. I still couldn’t really see it but nodded politely.

Now every new parent proudly shows the picture of their unborn baby which is as clear as new born baby photos.   

When I heard that the coronavirus tests were PCR it sounded as likely as my next holiday being on the moon.

I had come across PCR testing for DNA in the 1990s when I was working with the police but it was not a test which could be carried out cheaply or easily.

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The first time DNA testing was used in forensic medicine was in 1984 by Professor Alec Jefferies in Leicester. It was only 30 years since DNA itself had been discovered. 

In Torbay, the police started sending samples for DNA analysis towards the end of the 1980s.

It was amazing. It could pinpoint who had left any biological material but had limitations.

DNA is present in the nucleus of cells of the body. The hint is in the name. The NA of DNA stands for nucleic acid. But the red blood cells do not have a nucleus so no DNA. There are other cells in the blood with a nucleus but not as numerous as the red cells.

In the early days of DNA analysis we needed a blood sample the size of a postage stamp to get any DNA and it took a few weeks.

It also meant that forensic scientists could not extract DNA from sperm if the man had a vasectomy as there would be no sperm cells.

And it was very difficult to interpret samples from more than one person.

Nevertheless, as a new technique it was a fantastic breakthrough.

One police officer explained to me that in the past if a burglar had fouled the house he would be upset, now he’d smile and say 'great, we’ve got his DNA'.

Next came PCR, polymerized chain reaction. Although the technique was developed in 1983, it was not used in forensic medicine until the 1990s.

This involved taking the DNA and by repeatedly heating and cooling it in the lab the scientists could it get it to reproduce.

This meant that a tiny amount of DNA at a crime scene would be useful. But it was a very expensive technique which could take weeks. It also created problems. It was too good.

I was told about one case when the DNA from the cotton picker in Egypt was isolated from a swab.

Forensic science has moved even further forward with STR, SGM and SGM+ but this is beginning to sound like the acronyms in Line of Duty.

Using PCR testing for coronavirus means that a tiny amount of RNA can replicate itself so that there is enough to test.

And the number of cycles of heating and cooling needed gives an idea of the amount of virus present.

From an obscure expensive test taking weeks the scientists are carrying on thousands of tests and are under pressure to produce results in 24 hours.

It is also possible to analyse the RNA in detail so that new variants can be discovered.

When we celebrate amazing scientific developments, we should also celebrate how quickly the science moves from an obscure, expensive and time-consuming process to everyday routine.

Now that is discombobulating.