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COVID-19 Rapid Antigen Test

Mare St Clinic is now providing Covid-19 Rapid Antigen Testing in-clinic or from the safety of your own home. This test can prove essential for individuals who require regular Testing or businesses who are seeking to keep their employees safe.

Please do not book in for this test if you have symptoms. This test is not suitable for those who have COVID-19 like symptoms or for those who have had symptoms up to 28 days prior to the test – those that fall into this criteria should follow all government guidance regarding self-isolation and Testing via the NHS.

Price: £55 - In-clinic

Price: £19 - Home self-test Kit

Corporate Testing for the workplace 

If you are looking to incorporate regular Testing into your workplace environment, we are here to help. The rapid nature of our antigen test results allows for early detection of Covid so that that action can be taken swiftly. Committing to regular Testing demonstrates your dedication to providing a safe working environment. We specialize in evening and weekend testing for your teams. This ensures that those who work weekends or ever-changing shifts are tested appropriately as well. 


 Contact us to find out how we can help to keep you and your employees safe.

What is a Rapid Antigen Test?​

Rapid antigen testing is used for both points of care testing and Fit to Fly certification for France, Italy and America, among other countries. (Up to date guidance regarding entry requirements for countries outside of the UK can be found on the Government website).


We use a Lateral Flow Device manufactured by SD Biosensor; this test has obtained a sensitivity of 96.52% and a specificity of 99.68%. The test directly detects the presence of the genetic material/antigens of the COVID-19 virus, indicating whether or not there is an active infection. This test does not detect the presence of the body's immune response or antibodies. 

Where can I get my test?

We offer Testing in-store, as well as home and office visits, which will incur an extra charge. If you would like us to bring your test to you, get in touch with us directly, and we will be happy to help you with this.

* Please note: we only offer COVID Rapid Antigen tests in East and West London (E12, E6,  EC1, W12, W13, W14 etc).

How long does it take to get my results?​​

Your results will be produced within 30 minutes of your test. If your test comes back positive, you will be advised by the team regarding up-to-date Government guidance surrounding self-isolation. 

Before you get tested, we strongly advise that:


- A proof of identity will be required prior to having your sample taken. This can be an ID Card, Passport (required for travel certificate), driver's license, or residents permit. Unfortunately, we will not be able to assist you if you do not have any legal identification on you.


Nothing can go in the nose for at least 24 hours before Testing, including nasal medication, saline, hay fever sprays, cotton buds, etc.



This can inhibit the sample and mean that it needs to be retested or may not enable a conclusive result to be delivered.

* Important Note: Please read our T&C's before purchasing this product. If you proceed to "Book Now" below, you Read, Understood and agreed to our Terms and Conditions.

Alternative testing Options 

We understand that not everyone would like to use this form of Testing, and that is why we also sell test kits that allow patients to perform the test on their own. To find out more about this service, click here. 

Gathering Informations

COVID-19 Rapid Antigen Test

Frequently asked questions

What is a Lateral Flow Test?

The UK government is using Lateral Flow Tests as a quick way to determine if someone is infected with COVID-19, particularly asymptomatic carriers of the virus. Our lateral flow test involves taking a nasal swab and processing it using a small device that comes with the kit. It looks for a specific antigen, which is an indicator of the presence of COVID-19. The short processing time of this test makes it ideally suited for frequent testing, such as for travelers or in workplaces and educational institutes.

What is Day 2 Lateral Flow Certificate?

The Day 2 Lateral Flow Test replaces the prior Day 2 RT-PCR Test for incoming travelers who are fully vaccinated with an approved vaccine and coming from a country that is not on the red list. If the test result is negative, one does not have to self-isolate.
A Day 2 certificate is generated and supplied if the test result is negative. The Day 2 certificate includes your name, date of the results, passport number, date of birth, name of the test, and your test result, among other details that can be presented to authorities. It is signed by our lab's specialist.

​How long does it take to get the result of a Lateral Flow Test?

Our Lateral Flow Test takes no more than 15 to 30 minutes to provide the results. This is the amount of time it takes after you have taken the swab sample and finished the rest of the process.

​How does the Lateral Flow Test work?

You can buy the Lateral Flow Test from our Online Store — we are an accredited test provider with quick delivery of kits and turnaround time of results. To take the test, you are to follow the Lateral Flow Test instructions that come with the kit. These instructions include steps about how to take your swab sample, how to transfer the sample to the test cassette and relay it to us for digital confirmation.

Where can I purchase a Rapid Lateral Flow Test?

​You can buy the test from our Online Store with delivery guaranteed within 2-3 working days. Orders are also processed over the weekend to ensure we have them delivered to you on time.

​How long does it take to get the results of a Lateral Flow Test?

After you insert the swab sample in the extraction fluid, mix it, and put two-three drops of it onto the test cassette, it will take 15 minutes to get results.

What is the difference between Lateral Flow Tests and RT-PCR tests?

Both the RT-PCR and the Lateral Flow Test require nasal swabs, but the difference is in how the two are processed and the time they take. The RT-PCR test has to be sent to a lab for analysis, and it may take many hours to get the results. The Lateral Flow Test, on the other hand, is done entirely at home, and the results take no more than 15-30 minutes on average.A Lateral Flow Test is generally for people who are not showing any symptoms of COVID-19, whereas an RT-PCR is for people with symptoms. Moreover, since the RT-PCR test is more precise and accurate if you test positive on a Lateral Flow Test, you also have to take a further RT-PCR test for confirmation.

Should I get tested if I have no symptoms?

​Yes, you can be infected by COVID-19 and not have any symptoms. About 1 in 3 people with COVID-19 tend to remain entirely asymptomatic but can infect other people. Therefore, if you are traveling, or believe you have been in contact with someone infected with COVID-19, it is recommended that you get tested.

How can I perform this test on my own?

​The test has simple instructions and can easily be performed at home. It requires taking a nasal swab sample, which is then applied to the lateral flow cassette for results.

Can I take a Day 2 antigen test if I travel to the UK from a red list country?

​If you are traveling to the UK from a country that is on the UK's red list, you won't be eligible to take a Day 2 lateral flow antigen test. This applies to both vaccinated and unvaccinated people. Travelers from red list countries have to take a PCR test for the Day 2 and Day 8 tests and quarantine at a government-approved quarantine hotel.

​I tested positive on a Lateral Flow Test. What now?

​If you get a positive result on a Lateral Flow Test, you are required to self-isolate at once. You will then need to take a mandatory RT-PCR test for confirmation within 48 hours. You can get this test by ordering an RT-PCR home test kit from our online store.

What does it mean if my test results are 'void' or inconclusive?

You will get a 'VOID' or 'inconclusive' test result if your swab sample comes into contact with anything other than the inside of your nose. It will be contaminated and cannot be used to test for COVID-19 reliably. You can also get a 'void' result if you have an excess of mucus in your nasal cavity. It can also be due to a manual error in the testing procedure.In case of a void result, you will need to retake a swab sample with a new swab and try to ensure that you follow all the correct procedures to reduce the chance of getting a void result again.

My test result came back as positive. What now?

If your test result is POSITIVE. You and anyone else in your household must self-isolate immediately in accordance with Governmental guidelines.You will have to Report your lateral flow test results to the NHS, and you will also need to book an RT-PCR test for verifying the test results. You can arrange an RT-PCR test online or via phone by dialing 119.If your confirmatory RT-PCR test is also positive, you will be contacted by NHS Test and Trace, and you must enter self-isolation at home for a duration of ten days. Your self-isolation period will start from the moment you begin to experience symptoms of COVID-19. If you are asymptomatic, your ten days will start from the time your test was performed.You must not travel or meet anyone during self-isolation. Contact 111 if you need medical help, and in case of emergency, dial 999.If the confirmatory RT-PCR test is negative, you remain asymptomatic, and no one in your household has symptoms or tested positive, you and your household can stop self-isolating. However, you must continue to follow all other COVID-19 related government guidance to help protect yourself and those around you.For any further information, you can email us at or call us at 0203 488 7351.​

My test result was negative. What now?

If your test result is NEGATIVE, you will receive a confirmation of your results via email within 12 hours.Make sure to continue following all other COVID-19 related Government guidance to help protect you and those around you.If your Lateral Flow Test result is negative, but you are experiencing COVID-19 related symptoms, you should still self-isolate and book an RT-PCR test. If the RT-PCR test comes out negative and you remain asymptomatic, you can stop self-isolating.For any further information, you can email us at or call us at 0203 488 7351.

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