The test is designed to provide visual results within a window of 15 to 20 minutes after applying the specimen.
Positive test lines may begin to appear in as little as one minute, depending on the concentration of the target.
Negative results should only be confirmed after the full 20-minute wait time to ensure accuracy.
A timer should be started immediately after the specimen is added to maintain proper observation timing.
The reading window helps balance speed with the need for a reliable diagnostic indication.