A pregnancy test strip is designed to detect the presence of human chorionic gonadotropin (hCG) in urine. hCG is a hormone secreted by the placenta shortly after embryo implantation. The strip contains antibodies specific to hCG. When a urine sample is applied to the strip, the antibodies bind to hCG if it is present. This interaction produces a visible line or color change, indicating a positive result. In the strip control line reagents are typically antibodies or proteins that interact with a separate indicator to confirm that the test has been performed correctly. The control line ensures the test is working and provides a reference for interpreting the result.
