Lateral-Flow Immunochromatography
Definition
A test format in which a liquid sample flows laterally along a membrane, encounters labelled detection antibodies, and is captured at specific test lines by bound antibodies. Colour at the test line indicates the analyte is present.
- Flow direction
- Lateral, along a membrane
- Detection element
- Labelled antibodies plus capture antibody test lines
- Readout
- Visible colour change at test line
- Example products
- RSID-Blood, ABAcard HemaTrace
Common questions
How do RSID-Blood and HemaTrace differ despite using the same platform?+
They target different blood-specific proteins with different antibodies, glycophorin A for RSID-Blood and haemoglobin for HemaTrace, so they can give different sensitivity or specificity in aged, diluted, or animal-blood samples even though both are lateral-flow strips.
Why can lateral-flow blood tests cross-react with non-human blood?+
Because the target protein, such as haemoglobin, is structurally conserved across species, some strips can produce a weak or false positive with animal blood, so a positive screening result is generally followed by a species-specific confirmatory test.
Related terms
- Anti-Human Haemoglobin Antibody
- A monoclonal antibody raised against epitopes unique to human haemoglobin. Forms the detection and capture antibodies on the lateral-flow strip, conferring specificity...
- Control Band (C Line)
- A second line that captures excess labelled antibody regardless of whether the analyte is present. Its appearance confirms the assay ran correctly....
- Cross-Reactivity
- The capacity of an antibody raised against one analyte to bind structurally related compounds. In RIA, cross-reactivity is the main driver of...
- Prozone Effect
- A false-negative serological result caused by antibody excess. When antibody concentration is too high relative to antigen, antibodies saturate individual antigen molecules...
- Test Band (T Line)
- The line on the lateral-flow card that appears when the anti-haemoglobin antibody captures haemoglobin-laden conjugate. Its presence constitutes a positive result.