Lateral flow意思
"Lateral flow" is a term used in various fields, but it is most commonly associated with diagnostic testing, particularly in the context of rapid diagnostic tests (RDTs). In this context, lateral flow refers to a technology used in immunoassays, where a sample (such as blood, urine, or saliva) is placed on a test device, and the result is displayed on the same device in a short period, typically within minutes.
The lateral flow device consists of a strip of absorbent material (usually a nitrocellulose membrane) with different zones: a sample application pad, a conjugate release pad, a reaction zone, and an absorption pad. When the sample is added, it moves laterally across the strip by capillary action. Here's a simplified explanation of the process:
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Sample Application Pad: The sample is applied to this pad, which starts the flow.
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Conjugate Release Pad: This pad contains colored particles (usually gold or latex) that are conjugated with antibodies specific to the target analyte (e.g., a virus, bacteria, or a specific protein).
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Reaction Zone: This zone contains immobilized antibodies or other capture agents specific to the target analyte. If the target is present in the sample, it will bind to the conjugated antibodies.
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Absorption Pad: This pad ensures that all the liquid is absorbed, preventing it from dripping off the end of the device.
The result is typically read by the presence or absence of a colored line or zone, indicating a positive or negative result. Lateral flow tests are widely used for point-of-care testing in medical diagnostics, food safety, and environmental testing. They are popular due to their ease of use, rapid results, and ability to be used outside of a laboratory setting.
In other contexts, "lateral flow" might refer to the movement of fluids or particles in a direction parallel to the direction of the applied force, as opposed to "axial flow," where the movement is in the direction of the applied force.