How is an antigen test performed, and what do C and T represent?

Generally, antigen testing refers to SARS-CoV-2 antigen testing, where the C region represents the control line and the T region represents the test line. If both the C and T regions display red or purple bands, the result is positive; if only the C region displays a band, the result is negative; if only the T region displays a band, the result is invalid. The specific steps are as follows:

1. Wash your hands before starting the procedure and clean your nasal passages.

2. Remove the nasal swab, being careful not to touch the swab tip. Tilt your head backward and insert the swab 1–1.5 cm into the nostril.

3. Rotate the swab along the inner wall of the nasal cavity for 15 seconds, then remove it. Repeat the same procedure in the other nostril.

4. Place the sample-collected nasal swab into the specimen tube, rotate and stir for 30 seconds, then remove the swab.

5. Add the specimen solution into the test card and wait 15–20 minutes before reading the results.

It is recommended to perform this test at a reputable medical facility under the guidance of a qualified healthcare professional to ensure accuracy. If the test result is positive, seek medical attention promptly to avoid delaying treatment.