What is the main difference between PCR and serological test?

The health crisis that we are still experiencing has not only changed our social life in many ways, it has also prompted us to quickly familiarize ourselves with concepts that we didn’t know seven months ago.

Today, many are confidently using words and concepts such as COVID, pandemic, screening, epidemiology, social distance, or, two of the most common, PCR testing and serological testing.

But do we really know the difference between PCR and serological tests?

At Juaneda Hospitals, we have spoken to Francisco Javier Rascón, an internist at Juaneda Miramar Hospital, so that he explains us the main differences between the two tests, what they indicate and how they should be interpreted.

Two tests are currently the most popular: the PCR test, which uses a nasal swab sample, and the serological test, a blood test that measures the presence or absence of antibodies.

These are different tests that provide different information and need to be interpreted differently depending on what we want to investigate. That is why one cannot replace the other.

What is the PCR test for?

It is a test that looks for genetic material of the virus. Viruses are very small and tiny creatures that can only be made visible with a very powerful microscope.

Therefore, we have to look for the virus indirectly, starting with its genetic material. But what is the genetic material? It is a kind of identity card for every living being.

In the PCR test, we will use the sample we took from the nose to analyse and check whether there are very specific viral genes that are part of the genetic material of the virus. If these genes are detected, we assume the virus is present. With the PCR test, we know whether we are infected or not.

What is the serological test for?

It's a blood test that tells us if we have specific antibodies or not. But how do we find out?

Antibodies are proteins that are made by our immune system (our defences).

We can think of the immune system as a more or less specialized army. When viruses or bacteria enter the organism, special cells in this army begin to form antibodies.

antibody does not react to the coronavirus, only to the measles virus.

When we have an infection, the full arsenal of defences is deployed; the whole army starts and at a certain point in time it begins to form the antibodies.

If these antibodies are measurable, we will be able to determine that we were or are still infected. Based on the data, we can create a kind of time axis, depending on the phase of the antibodies, in which we will see at what point in time of the infection we are.

If you think you are infected, if you have had close contact with someone who tested positive or just want to check if you have antibodies, we have set up an exclusive zone at Juaneda Miramar Hospital for COVID-19 tests only.

With maximum safety, without an appointment and with results in less than 24 hours. Opening times Monday to Friday from 8 a.m. to 8 p.m. and Saturday from 8 a.m. to 3 p.m.

On the number 971 28 00 00, our team will answer the questions and resolve the doubts that both our patients and large companies may have about our COVID tests.

Here you can find all the information:

https://www.juaneda.es/promocion.php?promocion=4&lang=en

Juaneda, close to you.

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