About the Technology
Immunochromatographic assays, also called lateral flow tests or simply strip tests, have been around for some time. They are a logical extension of the technology used in latex agglutination tests, the first of which was developed in 1956 by Singer and Plotz.1 The benefits of immunochromatographic tests include:

1. User-friendly format.
2. Very short time to get test result.
3. Long-term stability over a wide range of climates.
4. Relatively inexpensive to make.

These features make strip tests ideal for applications such as home testing, rapid point of care testing, and testing in the field for various environmental and agricultural analytes. In addition, they provide reliable testing that might not otherwise be available to third world countries.

Test and control lines. These lines are typically an enzyme, antibody, antigen, or nucleic acid etc. These are immobilised on a membrane, usually made from nitrocellulose.

 

The principle behind the test is straightforward; Basically, Lateral Flow Immunochromatographic Assays are a simple device intended to detect the presence (or absence) of a target analyte in sample (matrix). Most commonly these tests are used for medical diagnostics either for home testing, point of care testing, or laboratory use. Often produced in a dipstick format, Lateral flow tests are a form of immunoassay in which the test sample flows along a solid substrate via capillary action. After the sample is applied to the test it encounters a coloured reagent which mixes with the sample and transits the substrate encountering lines or zones which have been pretreated with an antibody or antigen. Depending upon the analytes present in the sample the coloured reagent can become bound at the test line or zone. Lateral Flow Tests can operate as either competitive or sandwich assays.

< Prev		Next >