Do you know how to take a rapid antigen test (RAT) and read the result? RATs are a quick and convenient way to check if you have COVID-19. - A negative result is shown by a line next to the C marker and no line next to the T marker. - A positive result is shown by a line next to both the C and T markers. - If a line only appears next to the T marker, this means your test result is invalid. This can happen if the test was done incorrectly. If this happens, perform a second test by either retaking