How to diagnose COVID-19? Serology Analysis

What test should I have?

If you do not have symptoms and think that you may have been suffering from Covid-19 disease asymptomatically for more than 10 days, or think you may have passed it, you should have a serology test (blood draw) to determine the presence of antibodies ( IgM and IgG mainly).

The technique used in the qualitative test is the qualitative detection of differentiated IgG and IgM antibodies by means of lateral flow chromatographic immunoassay in samples of whole blood, serum or human plasma.

The technique used in the quantitative test is the enzyme microimmunoassay (ELISA). Unlike the qualitative one, it does not only give a positive or negative result, but it also gives the value (quantity) of antibodies detected. This helps define where the patient is on the immunity curve.

Frequently Asked Questions about the Covid19 Serology Test

How is the interpretation of the results?

IgM positive with IgG negative: We are in the presence of
Sars-Cov-2 virus infection.
IgM negative with IgG positive: The person has already developed
an infection by this virus but cannot be established
when. It has generated immunity although we do not know which one
will be the degree of protection or the duration of this.
Positive IgM with positive IgG: It means that the person
He has an active infection or is in a phase of early resolution.
IgM negative with IgG negative: The person does not have the
you have not had an infection in the past or if you have
had, has not generated detectable immunity.

Note: The test has a sensitivity of between 85% and
100% (this means that up to 15% of patients who
should be positive can give negative) and a specificity
between 98% and 100% (this means that up to 2% of
patients can present a positive result and actually
be negative).

How long does it take to give me the results?

The results take between 24 and 48 hours for the serology test and 48 hours for the PCR.

Test price

The price is € 60 for the qualitative test and € 80 for the quantitative test.

Where is the test done?

In our Hospital, Calle Arturo Soria 17, Madrid.

serology test

Qualitative and quantitative blood serology test

Serology blood tests seek to measure the level of certain immunoglobins, or antibodies, present in the blood. These antibodies have been developed by the body’s immune system to attack antigens (viruses, bacteria …)

Each immunuglobin that is generated serves to fight a specific antigen, the chickenpox antibody is different from that of mononucleosis, for example. The body can make mistakes and generate antibodies that attack the body itself, developing what is known as an autoimmune disease.

In relation to the covid-19 cornonavirus, 5 antibodies are developed at different times:

Immunoglobulin A (IgA)

Immunoglobulin G (IgG)

Immunoglobulin M (IgM)

Immunoglobulin E (IgE)

Immunoglobulin D (IgD)

A combination of 2 is always sought so that the diagnosis can be made either IgG or IgM and IgG.

The doctor will prescribe the test and you will have blood drawn from the tubes needed to perform the test.

The test is performed with a prescription.

This test is qualitative, and may have false negatives, so despite having a negative result, you must continue to take the precautionary measures recommended by the authorities. The quantitative test can also have false negatives, so they must continue taking the precautionary measures recommended by the authorities.

Remember to go to the center with a mask.