April 9, 2020

expert comment – what is an ELISA test?

There have been questions from journalists about what an ELISA test – one of the tests being used for COVID-19 – actually is.

Dr Elizabeth Bateman, Chair, Immunology Professional Group, Association for Clinical Biochemistry and Laboratory Medicine, and Rob Shorten, Chair, Microbiology Professional Group, Association for Clinical Biochemistry and Laboratory Medicine, said:

“An ELISA (enzyme linked immunosorbent immunoassay) is a commonly used test in diagnostic laboratories.  It involves using a protein from the virus to detect specific antibodies from the patient’s blood sample.  The amount of patient antibody is detected by a colour change; more colour means more antibody.  This method is used to measure antibodies in a wide range of conditions from autoimmune diseases (detecting antibodies to your own proteins), such as autoimmune thyroid disease through to antibody responses to pathogens such as hepatitis viruses.  ELISAs are usually carried out in diagnostic laboratories using automated machines.  The proteins and chemicals (reagents) used vary between the different tests and this results in varying test performance in regard to sensitivity and specificity.  Robust validation of these tests is therefore crucial to ensure that they are useful during the COVID-19 pandemic.

“We are unable to confirm what method of antibody detection is being used at Porton Down.”

The Association for Clinical Biochemistry and Laboratory Medicine (ACB) is a professional body dedicated to the practice and promotion of clinical science in the UK. The Association has medical and non-medical members in all major UK healthcare laboratories, in many university departments and in several commercial companies involved in healthcare. Read COVID-19 updates from our experts: www.acb.org.uk/whatwesay/covid19-updates

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.