Lateral Flow Assays (LFA) provide rapid, inexpensive and easy point-of-care testing of different analytes. They are well established as a valuable tool in medical, veterinary, food, agricultural and environmental settings. LFA tests typically comprise a plastic cassette, containing a strip of paper that can absorb and transport analytes to produce a visual result.
(1) The analyte from a given sample is first added to one end of the paper strip, where it is absorbed by the paper, allowing the target antigens to flow laterally along the test.
(2) These antigens first encounter and adhere to an area of conjugate antibodies and detectable tags bonded with the test.
(3) The antigens then migrate to an area of test antibodies that are highly specific to the antigen and actively bind to produce a solid, visible line that indicates a positive result, hence a confirmed presence of the target antigen. Secondary control lines can then be used to detect conjugate antibodies and ensure that the test is working correctly.