Hello everyone,

For this assignment, I will be explaining the term ‘lateral flow assay.’ For this reading situation, I would be a scientist explaining this word to potential employees interested in our product.

Parenthetical Definition:

Lateral-flow assays (medical test contained in a plastic cartridge) are used as a diagnostic tool (a test) used to determine the presence or absence of the target analyte (chemical molecule of choice) via allowing a liquid sample (test subject) to flow through a polymeric strip (plastic strip) upon which the sample can then interact with the test antibody (checks for molecule) and control antibody (serves as a control test).

Sentence Definition:

Term – Lateral-Flow Assay

Class – Medical diagnostic test

Distinguishing features – The lateral-flow assay uses liquid samples to measure for a target molecule through use of immuno-antibody reactions. It does not rely on strict environmental conditions or advanced tools to generate diagnostics, and is easy to both use and interpret results. Is cheap and quick to be produced.

Expanded Definitions:

A lateral flow assay is a diagnostics test that relies on immune-antibody reactions to give positive or negative results on the presence of analytes. Lateral flow refers to the method of how the sample is tested – the liquid flows laterally through the test cartridge, which allows the subject to reach various antibodies.

Lateral flow assays are popular due to lacking the need for advanced tools to give results. Additionally, they are cheap, fairly easy to prepare, and robust. However, some issues include difficulty of detecting multiple analytes, as well as only being fairly insensitive.

Generally, lateral flow assays are a plastic cartridge containing four distinct parts. The sample pad, the conjugate pad, the test membrane, and the adsorbent pad. The sample pad is a plastic pad that absorbs the liquid. The liquid flows to the conjugate pad, which allows antibodies to flow into the liquid. The liquid then runs through the membrane, upon which labels will detect antibodies. Excess liquid will then flow into the adsorbent pad.

Figure 1 – Components of a lateral flow assay

Source: Koczula, K.M., Gallota, A. (2016). Lateral flow assays. Essays Biochem. 60 (1): 111-120.

References:

Abingdon Health. What is a lateral flow test?. (n.d.). Retrieved Jun. 1, 2021, from https://www.abingdonhealth.com/services/what-is-lateral-flow-immunoassay/

Koczula, K.M., Gallota, A. (2016). Lateral flow assays. Essays Biochem. 60 (1): 111-120.

Sonano. Lateral Flow Assays. (n.d.). Retrieved Jun. 1, 2021, from https://sonanano.com/lateral-flow/