We provide a range of corporate COVID-19 testing kits for fast and reliable testing in the workplace, and coronavirus reagents for researchers to help you discover more about SARS-CoV-2, for less.
To help you understand the coronavirus products you are buying, we have compiled some of the most frequently asked questions about COVID-19 and the testing for it below, with clearly explained answers in non-technical language. If you have further questions about our testing kits, please contact us.
SARS-CoV-2 is the virus that causes the disease COVID-19. As a virus, it is a small infectious agent that cannot grow or multiply on its own. It instead invades living cells to highjack their replication machinery. Each particle of the SARS-CoV-2 virus is approximately 1/10,000,000 of a metre across, and is a roughly spherical shell made of lipids (fats) and four proteins, including the spike (S) protein. The S protein contains a key area, the receptor binding domain (RBD), that is used for infecting cells. This shell surrounds genetic material (RNA) that contains instructions for making more copies of the virus.
SARS-CoV-2 is short for severe acute respiratory syndrome coronavirus 2. It is commonly known simply as ‘coronavirus’, although it is actually only one member of the coronavirus family of viruses. It was first named 2019 novel coronavirus (2019-nCoV) and human coronavirus 2019 (HCoV-19) whilst scientists first studied and identified it.
COVID-19 is the disease caused by the virus SARS-CoV-2. It is a respiratory disease, meaning it affects the upper airways including the nose, throat, and upper parts of the lungs. It is usually a mild to moderate disease with symptoms including fever, a dry cough, and tiredness, and less commonly achiness, sore throat, diarrhoea, conjunctivitis (red, sore eyes), headache, a loss of taste or smell, and rashes. In severe cases it can cause difficulty breathing, chest pain, and a loss of speech and movement. It is currently causing a pandemic, meaning it has spread and is active across the world. COVID-19 is short for ‘coronavirus disease 2019’, named after the type of virus that causes it and the year it was first discovered.
Antigens are strictly defined as molecules which can cause an immune response, triggering the body’s defence system to target them for destruction and removal. When talking about SARS-Cov-2 antigens, we are usually referring to parts of the virus which are unique in their shape and structure, making them characteristic markers for SARS-CoV-2. These can therefore be used by the immune system to identify this virus, and tell it apart from other viruses. This is used in rapid COVID-19 antigen testing, where immune molecules (antibodies) that bind only SARS-CoV-2 antigens are used to identify this virus in a swab sample. Isolated antigens are also used in rapid COVID-19 antibody tests to detect SARS-CoV-2 specific antibodies in a blood sample, to diagnose a recovering or past COVID-19 case.
Antibodies are small molecules made by the immune system, the body’s defence system, which have very specific binding abilities. They are produced in response to an antigen, a characteristic part of a foreign substance, and they attach onto only that antigen. This is used by the immune system to detect and destroy disease-causing bacteria and viruses, to combat infections. The antibodies against the SARS-CoV-2 virus produced by the immune system can be detected by rapid COVID-19 antibody lateral flow tests to diagnose a recovering or previous COVID-19 case.
Antibodies against a chosen antigen can also be made industrially, and then used to identify that antigen in clinical testing. COVID-19 antigen rapid tests contain antibodies that bind only SARS-CoV-2 antigens, and so can be used to diagnose a current infection. Antibody production can also be stimulated artificially by a vaccine, so the person is better able to fight off an infection in the future.
Neutralizing antibodies are similar to other antibodies, except they bind onto a key part of a virus and block it from doing its job. Because this can stop the virus from infecting cells, neutralizing antibodies are a key part of building strong immunity against a virus.
In the case of the SARS-CoV-2 virus, this is usually part of the S protein called the ‘receptor binding domain’ (RBD). The RBD is used by the virus to grab onto ‘ACE2’ on the surface of the cells in the airways, so the virus can enter and infect those cells. Neutralizing antibodies block the RBD from binding ACE2, preventing an infection from even starting. These neutralizing antibodies can be detected using our Anti-SARS-CoV-2 Neutralization Antibody Test Kit, which can be used for fast preliminary screening of neutralizing antibodies, to estimate patients’ immunity levels to coronavirus infections. Immunity status should always be established using further laboratory testing, and all protective measures should still be followed after a positive test result.
Although research is still ongoing about COVID-19 neutralizing antibodies, current results show that most people who have had COVID-19 develop neutralizing antibodies which last for several months[1], and that DNA-based vaccines that encode the S protein can generate long-lasting levels of neutralizing antibodies[2], including the Moderna (mRNA-1273)[3] and Pfizer-BioNTech (BNT162b2)[4] vaccines[5]. There is evidence of a connection between levels of neutralizing antibodies and protection from COVID-19, but this is not yet strong enough to directly equate neutralizing antibody presence and immunity[1]. Neutralizing antibodies have previously been developed to treat other viral infections, so this might also be possible for SARS-CoV-2 in the future[6].
As the quarantine periods end around the world, testing for COVID-19 will be an essential part of preventing further outbreaks. We offer a range of rapid lateral flow testing kits for businesses and clinics to use, to enable you to be proactive in protecting your employees and customers. Learn more about our corporate COVID-19 testing kits here.
Antigens are parts of the SARS-CoV-2 virus that are unique in their structure, so by detecting them specifically, rapid antigen tests can identify a current COVID-19 case.
The virus infects the upper airways, so antigen samples are collected when swabs are taken from a patient’s nose, the back of their throat, and the back of their nasal cavity. The swab is then washed in treatment solution to suspend the virus particles in the liquid. A few drops of this are then placed into the sample well at the bottom of the test strip, and the absorbent layer draws the liquid up the strip. In the sample well area, the test strip has been sprayed with antibodies that latch onto the SARS-CoV-2 antigens, and no other parts of the sample. These antibodies are also connected to tiny specks of gold, called colloidal gold, that will become visible once collected in high numbers. The connected antigens, antibodies, and colloidal gold move together up the test strip with the liquid.
At the test area marked with ‘T’, the test strip is coated with a line of antibodies, which cannot move. When the liquid reaches the T area, these antibodies also latch onto the SARS-CoV-2 antigens. This connects the coated antibodies, virus antigens, and gold-labelled antibodies together, and these gather at the T area. The gold particles then become concentrated enough to be visible, creating a red line at the T area, to indicate a positive result for COVID-19.
If the patient is not currently infected, there will be no SARS-CoV-2 antigens in the sample. The gold-labelled antibodies will not be captured in the T area, and instead will spread across the test strip with the liquid. A red line will not be formed, indicating a negative result for COVID-19.
Antibodies are molecules made by the immune system, the body’s defence system, in response to an infection. They can latch onto parts of a virus, called antigens, and are specific for only one type of virus. COVID-19 antibody rapid lateral flow tests detect only antibodies for the SARS-CoV-2 virus, and so can be used to diagnose a recovering or past case of COVID-19.
Antibodies for COVID-19 circulate the body in the blood, usually from the end of the first week of symptoms. These can be detected in a drop of blood from a finger prick, or in a small amount of blood drawn using a needle from which the liquid part (serum) has been separated. When a few drops of this are placed into the sample well at the bottom of the test strip, along with a few drops of buffer liquid, the absorbent layer draws the liquid up the strip. In the sample well, the test strip has been covered with SARS-CoV-2 virus antigens, onto which the antibodies in the sample attach. These antigens are also connected to tiny specks of gold, called colloidal gold, that will become visible once collected in high numbers. The connected antibodies, antigens, and colloidal gold move together up the test strip with the liquid.
Human antibodies can be a few different types, but the ones made to combat COVID-19 can be IgG or IgM type antibodies. In the test area marked with “G”, the test strip is coated with a line of antibodies which cannot move, and which are able to bind only IgG antibodies. Similarly, the test area marked with “M” has been coated with antibodies that can only bind IgM antibodies. When the liquid reaches the test area, these stationary antibodies latch onto the IgG and IgM antibodies from the blood. This connects the coated antibodies, sample antibodies, antigens, and colloidal gold together, and these gather at the two test areas. The gold particles then become concentrated enough to become visible, creating a red line at the G area to indicate a positive result for IgG COVID-19 antibodies, and at the M area to indicate a positive result for IgM COVID-19 antibodies; either or both of these lines are evidence of a recovering or previous COVID-19 case.
If the patient has not been exposed to the SARS-CoV-2 virus, there will not be any antibodies for COVID-19 in the sample. The gold-labelled antigens will not be captured in the test areas, and instead will spread across the test strip with the liquid. A red line will not be formed, indicating a negative result for COVID-19.
COVID-19 neutralizing antibodies are a type of antibody which are able to latch onto an important part of the SARS-CoV-2 virus, the spike protein's receptor binding domain (RBD). They help prevent COVID-19 infections by directly blocking the RBD from binding ACE2, a protein on the surface of cells in the upper airways. COVID-19 neutralizing antibody test kits detect antibodies made by the immune system for the RBD, so can be used to estimate immunity levels.
Antibodies for COVID-19 circulate the body in the blood, usually from the end of the first week of symptoms. These can be detected in a small blood sample, using the liquid part of the blood with the cells removed (the serum or plasma). When a few drops of this are placed into the sample well at the bottom of the test strip, along with a few drops of buffer liquid, the absorbent layer draws the liquid up the strip. In the sample well area, the test strip has been covered with RBD molecules, onto which the neutralizing antibodies from the blood attach. The RBDs are also connected to tiny specks of gold, called colloidal gold, that will become visible once collected in high numbers. The connected antibodies, RBDs, and colloidal gold move together up the test strip with the liquid.
In the test area marked with “T”, the test strip is coated with a line of ACE2 proteins which cannot move. When the liquid reaches the test area, any RBD in the liquid will try and bind the ACE2. However, each RBD molecule can attach to either an ACE2, or a neutralizing antibody, but not both together. If there are no neutralizing antibodies present, then the gold-RBDs will bind ACE2, and collect at the test line; the gold particles then become concentrated enough to become visible, creating a red line at the T area to indicate a negative result for neutralizing antibodies. If the antibodies are present then these block the RBDs from binding ACE2, and the connected neutralizing antibodies, RBD, and gold spread over the test strip with the liquid; no red line forms, indicating a positive result for neutralizing antibodies.
Rapid lateral flow tests use a control line to prove the test has worked correctly, so you can trust the results you get. If the control line does not appear, then the result is invalid and the patient should be retested with a new test strip.
If no red line forms at the test area, this could be because the patient does not have COVID-19, and this is a true negative result. However, it could also be that an error occurred that stopped a positive result occurring, which is known as a false negative result. This could be because the liquid has not travelled far enough up the test strip, or the strip is damaged, or the antibodies in the strip have been over-heated and won’t bind the antigens any more, for example. It is impossible to tell a true negative and a false negative apart with only one test line, because they look the same.
A control line will always be visible if a test has worked correctly, for both positive and negative results. The exact mechanism used varies, but the control line always uses a similar antibody-based mechanism to the test line, so anything that stops the test line from working will also stop the control line from working, and a false negative can be identified. For full results interpretation guidance, please see the individual product pages.
Testing results can be best understood in terms of sensitivity and specificity. Sensitivity is how many people who actually have the virus get a positive result; a high sensitivity means the test is detecting the virus well, and cases won’t be missed. Specificity is how many people who don’t have the virus get a negative result; a high specificity means the test results won’t show cases that aren’t really there.
The best current test for COVID-19 is the PCR test, which is reported to have a sensitivity of 71-98%, and a specificity of 95%, based on several studies using controlled trial and real-world testing data. However, this is an expensive and much slower test, requiring samples to be sent to a laboratory. All of our COVID-19 rapid testing kits have high sensitivity and high specificity, judged against PCR testing results, which can be found on each product page. Our SARS-CoV-2 Antigen Rapid Test Kit, for example, showed in an updated clinical trial a sensitivity of 96.330% and specificity of 99.569% by comparing to PCR testing. The clinical report displayed with this product contains full details of how an earlier clinical trial was carried out.
The accuracy of any test is impacted by how well it is carried out and the quality of samples taken; all of our tests should be performed by trained medical professionals, following the instructions carefully. The accuracy will also be affected by the progression of the disease: antigen tests are most accurate when a patient has high levels of the virus in their body, normally the week surrounding the appearance of symptoms; antibodies are only produced and become detectable over a week after the first symptoms appear, and probably after the infection has largely receded. The test results therefore need to be interpreted in the full context of symptoms, possible exposure, testing procedure, and other tests taken. For more information and useful tools for understanding test accuracy, please see the British Medical Journal and the UK parliament page on testing accuracy.
Lateral flow tests are simple to use, with no special equipment needed, and no laboratory testing necessary. This means coronavirus testing can be done wherever it is needed: in a clinic, in an office, or on the worksite. COVID-19 lateral flow tests are also the fastest available way of testing, with a simple swab or finger prick sample collection process, and a rapid development period of only ten minutes. With an intuitive visual result, the outcome can be clearly understood by anyone. The lateral flow tests we provide for businesses have been validated against PCR laboratory testing and clinical diagnosis, so you can be assured of their accuracy.
COVID-19 lateral flow tests are therefore ideal for rapid case finding through mass screening at the first point of contact, quickly identifying those employees or customers who need to self-isolate.
We are licensed to sell COVID-19 lateral flow tests to businesses, for use under medical supervision. To order all of our COVID-19 lateral flow tests for corporate testing, please follow this link to our product page, and simply fill out the contact form.
Our coronavirus testing kits can be kept at room temperature (2-30°C), for up to 18 months from the date of production (please see the kit packaging). They do not need to be refrigerated, and should not be frozen.
All of our COVID-19 test kits come with test cassettes, testing solutions, tubes for extracting samples, droppers/tube caps for applying samples, and swabs for collecting samples (for antigen tests only).
The COVID-19 Rapid Test Kit IgG + IgM requires disposable sterile lancets for getting finger prick blood samples. These are widely available from pharmacists or online, for as little as a few pence each. The Anti-SARS-CoV-2 Neutralization Antibody Test Kit requires additional blood drawing equipment and a centrifuge to separate the plasma or serum from the blood cells.
All samples should be handled with caution, as if they contain infectious agents. Appropriate PPE should be worn, such as laboratory coats, disposable gloves, and eye protection. Observe established precautions against microbiological hazards throughout the sample collection and testing procedures, and follow the standard procedures for proper disposal of equipment and tests.
COVID-19 test results are available within 10 to 15 minutes, depending on the specific product you are using. Please check the product datasheet for details, which can be found in your kit or on the product pages, or contact us if you have any further questions.
Please follow the most up to date guidance in your country and local area.
In the UK, the current guidance for business performing COVID-19 testing is that used test cassettes and swabs should be classified as ‘Chemical’ waste, since the test procedure should render the material non-infectious. The tests and swabs should therefore be disposed of in unmarked yellow bags and sent to an ‘energy from waste’ (EFW) facility as a first choice, or a clinical waste incinerator. Used PPE should be treated as ‘offensive waste’, and disposed of in ‘tiger bags’, to be sent to EFW as a first choice, or landfill as a last resort. If the swabs, test cartridges, and PPE have become mixed, or separation is not possible, then all of these should be placed in a tiger bag and sent for EFW or clinical waste incineration. In order to reduce the strain on clinical waste incineration services, please separate waste where possible. Used lancets from finger prick tests should always be disposed of in a clinical sharps container. To check the arrangements and request collections in your local area, please see the government’s website on clinical waste services.
Please always follow your most recent government guidance when interpreting test results. For the UK, please see the NHS’s guide to coronavirus test results.
A positive COVID-19 antigen test result means you and anyone you live with should start self-isolating immediately. In the UK, the current advice is that the self-isolation period should include the day your symptoms started (or the day you had the test, if you do not have symptoms) and the next 10 full days. If you start getting symptoms while you're self-isolating, the 10 days restarts from the day after your symptoms started. Secondary PCR tests may be sought to confirm the positive result, which are available in the UK from the government coronavirus website. The positive result should be reported to your country’s test and trace system, to ensure any of your contacts that may also have contracted the virus begin isolating also.
IgG/IgM antibody tests are a bit different, as they check for antibodies against coronavirus, which normally appear a week after symptoms started and after virus levels have fallen. A positive COVID-19 antibody test result means you have likely had coronavirus before, even if you’ve not had symptoms, though it can’t tell you when you had it. It can therefore be used to track how infections spread, but does not mean you currently have COVID-19. You should continue to follow all social distancing measures, as the test does not guarantee you have immunity.
For the most recent information about the COVID-19 pandemic, including what to do if you get a positive test result, please follow the links below, or see your local government advice websites:
