How the coronavirus antibody test works

A test developed by Swiss drugmaker Roche can determine – with 99.8 percent accuracy – whether a person has already been infected with SARS-CoV-2* and may have developed an immunity to the virus


ELECSYS ANTI-SARS-COV-2 ANTIBODY TEST

1 Blood sample taken from patient and sent to laboratory

Antibodies
Antigen

Blood of patient that has been infected with virus will contain antibodies – proteins produced by human immune system to fight infection

2 Laboratory prepares sample by spinning it in centrifuge to obtain serum/plasma – liquid component of blood that contains antibodies

Serum/ plasma
Blood cells

3 Serum/plasma sample loaded into analyser and mixed with chemical reagents containing SARS-CoV-2 antigen – unique molecule that acts as target for immune response to virus

4 Antibodies in sample bind to antigens and chemical reaction produces light, which is detected by analyser

5 Test result comes back as either positive or negative for presence of antibodies, in about 18 minutes


Test works on Roche’s cobas e analysers, available in laboratories around world and capable of up to 300 tests per hour


*Severe acute respiratory syndrome coronavirus 2 


Picture: USAF/ Bryan Ripple
Source: Roche
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