Prozone Effect
Definition
A false-negative serological result caused by antibody excess. When antibody concentration is too high relative to antigen, antibodies saturate individual antigen molecules without cross-linking them, preventing lattice formation and the visible precipitation or agglutination needed to read a positive result.
Related terms
- 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...
- 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...
- Complement
- A group of heat-labile serum proteins (approximately 30 proteins, designated C1 through C9 in the classical pathway) that can be activated by...
- Complement Fixation
- The binding and consumption of complement proteins by an antigen-antibody immune complex. Once fixed, complement is no longer available for the lytic...
- 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....
- Indicator System
- In the complement fixation test, sheep red blood cells pre-coated with anti-sheep-RBC antibody (sensitised cells). These cells are lysed by free complement...
- Lateral-Flow Immunochromatography
- A test format in which a liquid sample flows laterally along a membrane, encounters labelled detection antibodies, and is captured at specific...
- Postzone Effect
- A false-negative serological result caused by antigen excess. When antigen greatly exceeds antibody, both binding sites on each antibody molecule are occupied...
- 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.
Explained in these topics
- Complement Fixation and Mixed Antigen-Antibody ReactionsA false-negative serological result caused by antibody excess. When antibody concentration is too high relative to antigen, antibodies saturate individual anti...
- RSID-Blood and ABAcard HemaTraceParadoxical inhibition of the test band when haemoglobin concentration is extremely high, as excess antigen saturates all antibody binding sites and prevents t...