What does the T and C stand for on a Covid test?
Positive result. Two lines appear. One coloured line should be in the control line region (C), and another coloured line should be in the test line region (T). Two lines, one next to C and one next to T, even faint lines, show the test is positive. If you test positive, you and your.
This is what the test “window” looks like in the strip after 30 minutes. “C” stands for “control” – this is to make sure the test is working. “T” stands for “test” – this is where your sample result will appear.
Read results after 15 minutes. One red line (C) - indicates a neg- ative result, Two red lines (C and T) - indicate a positive result. One line (T) - is an invalid test (re-do the test). COVID-19 Self-Testing Instructions. BTNX Rapid Response™
Rapid antigen or lateral flow tests can help to identify when someone with COVID-19 is most infectious, but even a faint line should be treated as a positive result. 18 November 2022.
A POSITIVE result must show BOTH a C line and a T line. A positive result means the individual is positive for COVID-19.
If only the control line (C) is present, the result is negative. If both control line (C) and test line (T) are present, the result is positive. or • If the control line (C) is not present, result is not valid (i.e., the test is not working).
Any visible pink/ red “T” line is a positive result when the “C” line is also present. A positive test result means that the virus that causes COVID-19 was detected in your sample and it is very likely you have COVID-19 and it is important to be under the care of a healthcare provider.
Two lines – even faint lines – indicate the test is positive. The test has failed and should be retaken.
Two lines – even faint lines – indicate the test is positive. The test has failed and should be retaken.
A POSITIVE result must show BOTH a BLUE line and a PINK line near the BLUE line. Look closely! Even a very faint, pink Test Line and a blue Control Line is a POSITIVE result. The intensity of the lines may vary.
What is C and T on art test kit?
If you see a line appearing at. only the “C” position, this indicates a negative test. If you see a line appearing at. only the “T” position, the test is invalid.
A colored line should always appear at the C position; this is the control line and signals that the test is working properly. If a control line (C) is visible (regardless of how faint it is) and a test line (T) is not visible, this means that the result is negative. It is unlikely that you have COVID-19.

Only 1 line next to the letter T • No lines at all If there is no line or colour next to the letter T your test is negative. You do not have COVID-19. If there is a line or any colour next to the letter T your test is positive.
There are several possible explanations for why you might get negative rapid tests even when you have COVID-like symptoms. The most likely is that you have an infection of something other than SARS-CoV-2. Many different viruses and bacteria can make us sick.
References
- https://www.ontariohealth.ca/sites/ontariohealth/files/2021-10/BTNX%20Self%20Screening%20Instructions_v4.1.pdf
- https://www.mass.gov/doc/covid-19-self-test-instructions-english-bw-022222/download
- https://www.cheney.oxon.sch.uk/wp-content/uploads/2021/03/Understanding-Lateral-flow-Antigen-Testing-Cheney-2021.pdf
- https://www.england.nhs.uk/coronavirus/wp-content/uploads/sites/52/2020/12/NHS-Test-and-Trace_HEE_PC-staff-testing-LFD.pdf
- https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1045088/COVID-19-self-test-throat-and-nose-instructions.pdf
- https://www.health.gov.au/sites/default/files/documents/2022/02/how-to-do-a-rapid-antigen-test-from-your-nose-easy-read-how-to-do-a-rapid-antigen-test-from-your-nose.pdf
- https://www.fda.gov/media/155126/download
- https://www.fda.gov/media/155175/download
- https://www.umassmed.edu/news/news-archives/2022/10/covid-19-rapid-tests-can-breed-confusion/
- https://www.england.nhs.uk/coronavirus/wp-content/uploads/sites/52/2020/11/LFD_NHSStaff_A4_161120_.pdf
- https://www.mom.gov.sg/-/media/mom/documents/covid-19/posters/antigen-self-test/sd-art-english.pdf
- https://www.gavi.org/vaccineswork/does-faint-line-covid-19-test-mean-im-no-longer-infectious
- https://www.fda.gov/media/146313/download
- https://www.saskatchewan.ca/-/media/files/coronavirus/testing/self-testing/t2p---rat---btnx-rapid-response.pdf