Back to Lab Antibody Testing
THIS IS AN ELISA BLOOD SAMPLE TEST THAT HAS TO BE CARRIED OUT BY A TRAINED PHLEBOTOMIST OR
OTHER QUALIFIED HEALTHCARE PROFESSIONAL
IT IS NOT A SELF TEST OR RAPID TEST KIT
The test is CE marked and the analysis is carried out at an ISO15189 accredited laboratory in Europe
IF YOU WOULD LIKE TO WORK WITH US ON THIS SAMPLING AND TESTING PROJECT THEN PLEASE GET IN TOUCH
Screen4 can provide access to the latest revolutionary testing technology which can identify and confirm the presence of antibodies of COVID-19 (SARS-CoV-2), the new strain of coronavirus.
Up to now there has been huge publicity surrounding the governments testing strategy to determine if someone currently has a Covid-19 infection. We have helped to deal with some of this demand by providing access to a CE approved and reliable PCR back to lab test. Our COVID-19 PCR analysis is in line with PHE and NHS protocols.
In addition to the requirement for an accurate PCR test, there has been a huge focus on ‘antibody tests’ that will demonstrate if an individual has started to develop or has a possible immune response to SARS-CoV-2- (COVID-19). This is a clear sign that they have be infected at some stage recently.
These tests will play a crucial role in assessing the level of antibodies across in the, responses to vaccines and potentially as part of any return to work strategy SEE ADDITIONAL INFORMATION. This information will be key in understanding your risks.
Anti-body Testing Options:
There are broadly two different ‘antibody tests’ using different detection methods:
- Lateral-flow assay
- A lateral flow assay can be done as a simple, rapid diagnostic, point-of-care test. It can be self-administered, and results obtained I around 15 minutes. They provide a binary outcome-positive or negative – with no quantitative information. These are predominantly unreliable as a test due to wide variance on their accuracy and are NOT recommended to be used by PHE or UK Gov.
- An ELISA- (enzyme-linked immunosorbent assay) based test involves a blood test with laboratory analysis. It can provide accurate quantitative information. An ELISA-based test will be more sensitive than a lateral flow assay due to the longer incubation times that are possible with the former. These tests can be quantifiable to provide more informative data to assist in assessing the status of an individual. The tests are CE marked and is recommended to be carried out in an accredited laboratory (ISO 15189). – The analysis of both IgA and IgM antibodies can be carried out to determine the ‘stage’ of a person’s infection or antibody levels at that time. (Subject to clinical interpretation)
How the test works:
This test requires a blood draw (serum sample) and must be carried out by a phlebotomist or similarly qualified person – awareness of appropriate PPE and risks must be taken into account. The method of testing uses the ELISA platform for the detection of both IgA and IgG antibodies present in the blood sample.
Once the sample is collected then the sample is sent via courier to the laboratory.
Laboratory turnaround time is estimated as 2 to 3 days from receipt at the lab – this may vary dependent upon the capacity and workload at any given time.
Progress From Infection To Supposed Immunity
1. This is the overall process from initial exposure / symptoms and potential (supposed) immunity. The times are estimated and are based on the latest data available. This timeline may change based on updated data.
2. This shows the key stages and profile of the viral load increase during the infections stage and subsequent reduction of Viral load. This then gives way to potential antibody development in an individual.
3. This diagram shows the methods of testing that give insight to the stage in the overall process as in Fig1 . At the early stage the most reliable test method is PCR analysis and as can be seen from Fig2 there is an overlap of timing from one stage to another.
If there is any doubt regarding the transition / timeline then we would suggest that BOTH tests – a PCR and Antibody ELISA test be carried out at the same time – this will provide the most comprehensive picture of an individuals status regarding the infection.
Correct application of our tests
- Identification of an acute infection by direct virus detection by PCR: SARS-CoV-2
- Further monitoring of patients with acute infection (confirmed by positive PCR): Antibody detection using the Anti-SARS-CoV-2 ELISA (IgA)
- Detection of a past contact with the pathogen (from 2 to 4 weeks after infection): Antibody detection using the Anti-SARS-CoV-2 ELISA (IgG)
Interpretation of SARS-CoV-2 test results. The possible combinations of outcomes from the PCR and ELISA Antibody tests are shown below: please note that these are indicative outcomes and all results should be discussed with your clinician / doctor / Consultant following reporting of results.
Anti-SARS-CoV-2 ELISA (IgA)
Anti-SARS-CoV-2 ELISA (IgG)
Early phase of acute infection (up to day 10)
Late phase of acute infection (from day 10)
No statement possible
Characteristics of Screen4 SARS-CoV-2 tests
- IgG: High specificity of 99 % * due to the use of the spike protein domain S1, which is hardly conserved within the coronavirus family; suitable for identification of persons who had contact with the virus some time ago
- IgA: Supportive analysis of follow-up samples after infection confirmed by PCR; indicates a beginning immune reaction.