Coronavirus Testing

Greenfields currently offer three types of testing for SARS-CoV-2 (COVID-19):

  • PCR testing (for those with active disease symptoms)
  • Antibody testing (for those who have had symptoms in the past or may have been exposed but have no symptoms)
  • T-cell reactivity to SARS-CoV-2 for those with low levels of antibody or mild disease to check for previous exposure 

For patients in the UK our laboratory partner is ArminLabs in Germany, which has a long history of testing for viruses, bacteria and parasites.

Read more about the three types of testing below.

PCR Testing

The PCR testing method (Polymerase Chain Reaction) is a genetic test for the specific RNA (ribonucleic acid) of the coronavirus SARS-CoV-2. PCR is a nucleic acid amplification technique, which is amongst the most reliable COVID-19 tests for diagnosing current infection. These tests can be used to directly detect the SARS-CoV-2 virus in people who are currently infected persons, using a throat and nose swab or throat lavage. All tests for COVID-19 should be performed in coordination with a healthcare provider.

The sample required is 1 x throat lavage tube with 50ml of salt water solution. Taking the sample at home is a quick and easy procedure. If you are suitable for testing, the kit comes with full instructions and will be sent to you at home. A courier will be ordered the day before taking the sample, to collect the kit and take it to ArminLabs for testing. The results will be reported by the lab on the day the sample is received.

T-Cell Immunity Testing

When T-cells in the immune system recognise a pathogen such as a virus they can divide into Th1 and Th2 cells which produce different cytokines (signalling molecules).

Th1 triggers a response by the body's immune T-cells (cellular response) and Th2 trigger the production of antibodies (an acquired or humoral response). T-cell reactivity testing uses detection of two cytokines, the signalling molecule IL-2 which stimulates the activation of T-cells and production of memory cells, and INF-γ, which is produced by activated T-cells. Evidence of memory cells shows that there has been a previous infection with the Sars-CoV-2 virus that has triggered the cellular immune system, and these cells are known to last for many years, as evidenced by the presence of memory cells still found in people who were infected by SARS 1 in 2003. 

T-cell testing uses the CoV-iSpot test, which has often shown reactivity in patients with a previously mild infection, because a T-cell response can clear the infection before the body starts to produce antibodies. the CoV-iSpot test is very specific, and can differentiate between Covid-19 and influenza infections. 

This test is carried out using a blood sample from the vein. We are not currently offering blood draws to patients who have symptoms of active infection due to the requirements for extensive PPE and isolation from other users of the clinic. 

Antibody Testing

When you are infected with a virus the body responds by making specific immune system memory proteins (antibodies) to attack invaders such as bacteria or viruses. After infection with the virus these proteins remain in the blood. A test can determine who has already had the virus or been exposed to it by searching for levels of antibodies.

There are three types of antibodies produced by the body that can be tested, which take different times to become evident in the blood, and stay in the blood for different amounts of time:

  • IgM is the first antibody produced upon infection
  • IgA is produced by the mucous membranes, and is present after IgM can be detected
  • IgG is a longer-lasting antibody produced after IgM

N.B. There is currently no evidence that having antibodies to SARS-CoV-2 confers immunity from future infection with the virus (although the development of a vaccine would presuppose that this would be the case), and if so, for how long immunity might last, as there is a possibility that the virus might mutate into a form which is not recognised by the antibodies.

Getting Tested
Why get a test for SARS-CoV-2?

Appropriate testing:

  • Differentiates SARS-CoV-2 from other acute pulmonary infections such as the influenza virus
  • Provides diagnostic assistance in the event of new infections
  • Can document a current or previous infection approximately 2 - 3 weeks after the onset of symptoms
  • Provides Documentation of an immune reaction and possible immunity

If you require a sample kit to test for active coronavirus infection this can be sent to your home after a video or phone consultation. We will order a courier to collect the sample kit and deliver it to the laboratory the next day, your test results will be sent to you as soon as we receive them, and followed up with a video or phone call to discuss the results.

2 - 3 weeks after the onset of symptoms and 4 - 5 weeks after exposure, almost 100%. of people produce detectible antibodies. If you require a sample kit for coronavirus antibodies for past infection you will need to come in to the clinic to give a blood sample. This will either be tested in the clinic or sent to the laboratory for testing.

In certain circumstances you may wish to get tested by both PCR and antibody methods. In this case where you may have active infection we can make arrangements to carry this out in your own home.

Ordering a PCR Test

A PCR test can be used as a Fit to Fly certification. However we are no longer able to provide fit to fly tests due to new certification requirements in 2021

If you have symptoms which could be associated with coronavirus COVID-19 do not come in to the clinic, we will send you a sample kit to use at home.

Symptoms may include the following:

  • Fever (above 39ºC/102ºF)
  • Persistent cough
  • Phlegm with or without blood
  • Muscle aches or headaches
  • Fatigue or exhaustion
  • Loss of or change in taste or smell
  • Shortness of breath or difficulty breathing
  • Sore throat
  • Runny nose
  • Jaw or facial pain
  • Loss of appetite, nausea or vomiting
  • Diarrhoea
  • Conjunctivitis

Book online or call the clinic on 01227 454 848 to make a video appointment or phone consultation to discuss your symptoms and suitability for testing. If you are a candidate for coronavirus PCR testing we will arrange delivery of the test kit for yourself and any other members of your household, and a courier collection to take the samples to the lab.

When the results are ready a video appointment or phone consultation will be arranged to explain your results to you and what you should do next.

Book a Video Call Online
Ordering an Antibody Test

Antibody testing can be done 2-3 weeks after the onset of symptoms, or 4 -5 weeks after exposure.

  1. We will go through the COVID-19 symptom checklist during a video or phone consultation for antibody testing for the following people:
    • Patients who have previously tested positive via a PCR swab test
    • Patients who have previously had COVID-19 symptoms
    • Those from high risk groups who have had contact with patients infected with the COVID-19 virus
  2. If a past infection is suspected with no signs of current infection, we can do the testing in the clinic or take a blood sample and send it to the laboratory to check your immune response
    • We can take a fingerprick blood sample and do the SARS-CoV2 IgG/IgM rapid test in the clinic to get results within 15 minutes. We will provide you with a copy of the test form with a positive or negative test result
    • We can take a blood sample from your vein and send the sample to the laboratory to run the SARS-CoV2 IgG/IgA ELISA antibody test. You will get an official medical certificate from ArminLabs with a positive or negative result for COVID-19
  3. We will interpret your antibody test results and discuss the implications with you

Older people, and patients with underlying medical conditions (such as hypertension, cardiac issues or diabetes, cancer, another active infection and/or those suffering from immunosuppression) may be subject to a more severe course of COVID-19. Self-isolation, with limited exercise and a suboptimal diet during this period may lead to further deficiencies. In these cases ArminLabs recommends checking additional parameters, including:

  • CD3+/CD56+/CD57+ cell count - these are natural killer cells involved in fighting viruses and other infections
  • Zonulin (intestinal permeability)
  • Vitamin D3

Call the clinic on 01227 454 848, email us for a call back or use our online booking system to make a video appointment or phone consultation to discuss your symptoms and suitability for testing.

Schedule a Video Call Appointment Schedule an In-Person Appointment
PCR Testing: Technical Details
Real-Time PCR (Polymerase Chain Reaction) Test
For initial diagnostic testing for COVID-19, the World Health Organisation (WHO) and the US Centers for Disease Control and Prevention (CDC) recommend collecting and testing an upper respiratory specimen. The nasopharyngeal specimen is the preferred choice for swab-based SARS-CoV-2 testing, and throat swabs (posterior pharyngeal swab, avoiding the tongue) are also recommended in addition. The collection of a combined nasopharyngeal and pharyngeal swab is uncomfortable, complicated to perform, and should only be taken by trained professionals. ArminLabs, in cooperation with the test manufacturer, has established and validated an equivalent method of taking a sample that can be performed by yourself at home. Since a high concentration of viable SARS-CoV-2 virions can be found in the throat and sputum within the week after the symptoms first appear, ArminLabs also offers PCR testing using a throat lavage solution to be used during this time. A preprint (not yet peer-reviewed) paper found that saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs for PCR testing.

The Nucleic Acid Amplification Technique is the most reliable test for diagnosing current infection with SARS-CoV-2, which is the method used in the Real-Time PCR (Polymerase Chain Reaction). This test can be used to directly detect the SARS-CoV-2 virus in infected persons using a throat swab, nose swab, and/or throat lavage.
This test may be used when your patient is currently showing symptoms of the virus. It should be done right at the start of suffering from symptoms.
There are two ways this test can be carried out:
  1. As a nasopharyngeal swab or posterior pharyngeal swab (avoiding the tongue).
  2. Because the above is uncomfortable and may be particularly difficult for children, ArminLabs offers RT-PCR as a throat lavage solution. It has been established that a high concentration of SARS-CoV-2 viruses may be found in the throat and sputum within the first week after the first symptoms appear.
The sample needs to be returned to the laboratory for evaluation as soon as it has been obtained via our courier service.
The result is reported as positive or negative and will be available on the same day that the samples arrive at the laboratory.

Antibody Testing Technical Details
SARS-CoV-2 ELISA IgG and IgA Antibody Testing and SARSPLEX test


This test measures IgG and IgA antibodies against SARS-CoV-2, the virus that causes COVID-19. The test is conducted from serum (SST tube, no centrifuging necessary) at the laboratory in Germany, and a laboratory report is provided as an official document.

Seroconversion takes place with almost 100% certainty after around three weeks.

IgA is commonly seen as more immediate, and reflects antibodies along the mucosal membranes. IgA may appear after 3 days (some reports), but more likely after 10 days. Specificity of the IgA antibodies test is 87.5 – 100%

IgG is the long-term antibody that appears later, and traditionally indicates a degree of immunity (though this is still being studied in the case of this new virus). Specificity of the IgG antibodies test is 83.5 – 97.5%

This test has been developed in Germany and is CE certified and IVD (In Vitro Diagnostics) registered and validated.

The SARS-CoV-2 ELISA can be negative, borderline, or positive, for either or both immunoglobulins.
The result will be ready 1 – 2 days after the sample arrives at the laboratory. The report gives reference ranges and figures (i.e., it is not just reported as positive or negative).


ArminLabs now also has the SARSPLEX test for SARS-CoV-2 which incorporates 2 antigen structures (n- and s-) for all three immunoglobulins. The test is conducted from serum at the laboratory in Germany, and a laboratory report is provided as an official document.

SARSPLEX incorporates both the spike (S1 subunit) antigen, and the nucleocapsid protein (N) for better sensitivity, specificity and robustness in diagnosis. In addition, SARSPLEX test for IgM, IgG and IgA immune responses against SARS-CoV-2.

The test is CE certified as well as IVD registered and validated.

T-Cell CoV-iSpot Test Technical Details

The CoV-iSpot developed by the company AID detects the IFN-γ and IL-2 reactions of pathogen-specific activated T-cells against SARS-CoV-2 (SARS-CoV-2 peptide mix) and coronaviridae in general (PAN-Corona peptide mix). The SARS-CoV-2 peptide mix developed by the company AID contains only highly specific sequences of the immunodominant epitopes of SARS-CoV-2. To differentiate it from other coronaviruses, a second peptide mix with specific sequences of conserved regions within the family of coronaviridae (PAN-Corona Peptide Mix) is included in the CoV-iSpot. A double determination in the testing system using both positive and negative controls is used to make the test as accurate as possible. 

Our Testing History
External and In-House Laboratories

In addition to using a wide range of external conventional pathology laboratories and specialist functional laboratories we also have been offering blood grouping tests from our own in-house laboratories for over a decade to complement our nutritional consultation services. 

Other Health Conditions
We can test for an extensive range of conditions in addition to coronavirus

Greenfields can access tests for all health requirements. We are also agents for sexual health screening services, testing for sexually transmitted diseases. Please enquire about our complete range of testing services. 

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