LFAs utilize a combination of antibodies and color-change technology to provide qualitative or semi-quantitative results. The core components include a sample pad, a conjugate pad containing labeled antibodies, a nitrocellulose membrane with immobilized capture antibodies, and an absorbent pad. When a sample is applied, it migrates through the device by capillary action. If the target analyte is present, it binds to the labeled antibodies, forming complexes that are captured by immobilized antibodies on the test line, leading to a visible signal.
