The question of whether the C line or T line is positive depends on the context of a test, specifically in scenarios like lateral flow assays (e.g., rapid antigen tests). In these tests, a positive result is indicated when both the Control (C) line and the Test (T) line are visible.
Here's a breakdown of what each line signifies and what it means for the test outcome:
Understanding the Lines
| Line | Meaning |
|---|---|
| Control (C) Line | This line is a procedural control, indicating that the test has been performed correctly and the reagents are working as intended. It must be visible for the test result to be valid. |
| Test (T) Line | This line appears only if the target substance (e.g., antigen) is present in the sample at a detectable level. A visible T line indicates a positive result. |
Interpreting the Results
According to the provided reference:
- If the Control (C) line and the Test (T) line are visible, the test is positive. Any faint visible test (T) line, along with the control line (C), is considered a positive result.
- A positive result means that the target substance being tested for is present in the sample.
- A positive result at any time during testing means repeat testing is unnecessary.
