HOW TO USE AN AT HOME COVID-19 RAPID ANTIGEN TEST CORRECTLY?
COVID-19 rapid antigen test kits are lateral flow diagnostic devices which qualitatively detect SARS-CoV-2 spike or nucleocapsid protein in human nasal, nasopharyngeal, oropharyngeal or saliva samples. These tests can check for the presence of an active COVID-19 infection on the spot and deliver results in 15 to 30 minutes. Recently, COVID-19 rapid antigen test kits have become available for the public as at-home tests. As these kits are deliberately designed for self-administration, they do not require additional equipment or special training for the application, procession, and the interpretation of the test. Here, the correct way to use an at-home COVID-19 Rapid Antigen Test will be explained.
How To Store At-Home Rapid Antigen Test Kits?
At-home COVID-19 rapid antigen test kits typically requires a storage temperature between 2°C – 30°C. The kit should not be stored in the freezer or exposed to direct sunlight. The kit must be brought to room temperature prior to testing.
The kit should not be used after expiry date provided on the packaging.
The test cassette must be used within 15 minutes after it has been removed from its packaging.
Preparation for Testing
At-home COVID-19 rapid antigen test kits typically contain a test cassette, a sterile swab, a bottle of extraction buffer, instructions for use (IFU) and a waste bag. You should not conduct the test if you notice any damaged or missing items.
While the procedure is generally quick, risk-free, and easy-to-follow, to ensure maximum accuracy and safety, it is recommended that you familiarize yourself with the material and procedure in advance. Instructions may differ depending on the specific test, so please make sure to read the instructions for use (IFU) document provided within the kit carefully before performing a test.
To prevent contamination, make sure to perform the test with clean hands and on a clean surface. You should clean and dry a flat surface to lay all the components on and clean your hands with soap and warm water or sanitize your hands before you start the procedure. It is recommended that you finish the test within 30 minutes after opening the kit.
Sample Collection and Processing
First, open the bottle containing the extraction buffer and place it into the tube holder.
Find the sterile swab and carefully remove it from its sealed packaging. You should make sure that the fabric tip of the swab does not meet your hands or other surfaces. Any contact with hands or objects may contaminate your sample and lead to invalid or inaccurate results. Accordingly, you should only remove the packaging of the swab and other components when you are ready to perform the test.
Next, gently insert the sterile swab around 2.5 cm into one nostril and rotate the swab a few times close to the inner wall of your nose as instructed. Repeat the same step for the other nostril. For the best results, gently blow your nose before you collect a nasal sample. While this procedure may feel a little uncomfortable, do not insert the swab any deeper if you experience strong resistance or pain.
Then, insert the swab into the extraction buffer tube and dip its fabric tip into the buffer solution. Press the tip of the swab against the inner wall of the tube and rotate the swab for a few times as instructed. This step transfers your sample into the extraction buffer.
Pinch the upper half of the swab to remove it, leave the other half in the tube, and close the cap tightly to prevent leaks. Mix the tube and carefully break off the tip of the cap.
Remove the test cassette from its packaging and gently squeeze the extraction tube to add 2 -3 drops of the solution into the sample well (S).
At-home COVID-19 rapid antigen tests typically deliver results within 15 to 30 minutes. Make sure to read the results within the time specified in the instructions.
How to Interpret Your Results?
The presence of the control line (C) indicates the successful penetration of the test sheet by the sample, the reactivity of the reagents, and proper test performance. If the control line (C) does not appear on the test cassette, the test results are considered invalid.
The presence of both the control line (C) and the test line (T) indicates a positive result. This means that you have an active infection with SARS-CoV-2.
If only the control line (C) appears, the test result is negative. To rule out the possibility of an infection altogether, you might need confirmatory testing either by a PCR test or by serial antigen testing.
For the safe disposal of the kit, put each item into the waste bag immediately after using it, seal the bag and dispose it promptly in the general waste bin. Finally, make sure to clean or sterilize your hands and the surface after finishing the test.
What Are the Factors That Can Affect Test Performance?
Studies suggest that one of the most decisive determinants of the performance of an at-home rapid antigen test is the patient’s viral load at the point of testing. Therefore, factors that affect the viral load such as your immune status, your vaccine status, and the time from illness onset may have an impact on the overall performance of your test. The performance of an at-home rapid antigen test may also be influenced by its sample type, its target antigen, along with its product design and material quality. Early evidence suggest that some sample types may be more suitable for the detection of some variants of SARS-CoV-2. Finally, the performance of an at-home rapid antigen test may be limited by the lack of training or competency of the test administrator. You can make the most of your test by ensuring proper sanitation, sample collection, administration, and interpretation. To receive the most accurate results, you must make sure that you perform each step of the procedure as instructed. Store the kit as instructed. Do not keep it in the freezer, and make sure to use the kit in room temperature. Check the expiry date of the kit and make sure that all the components are present and undamaged. Clean your hands and the surface thoroughly immediately before starting the procedure. Finish the procedure within 30 minutes, and only read the results within the time frame specified in the instructions.