Monoclonal Antibody
Definition
An antibody produced from a single B-cell clone, recognising a single specific epitope. In forensic species identification, monoclonal antibodies offer higher specificity than polyclonal antisera, reducing cross-reactivity. They are the basis of modern commercial ELISA kits and lateral-flow strips validated for species-specific proteins such as muscle myosin or serum albumin.
- Source
- Single B-cell clone
- Binding
- Recognises one specific epitope
- Advantage over polyclonal antisera
- Higher specificity, less cross-reactivity
- Common application
- ELISA kits and lateral-flow strips
- Forensic targets
- Species-specific proteins (e.g., muscle myosin, serum albumin)
Common questions
Why does higher specificity matter for a forensic species test?+
A test with cross-reactivity might give a false positive for the target species when a related species is actually present, which could be significant in wildlife crime or food fraud cases where distinguishing closely related species is the whole point of the test. Monoclonal antibodies reduce that risk because they bind only one precise epitope.
What is the practical difference between a monoclonal and polyclonal antibody test in casework?+
A polyclonal antiserum contains a mixture of antibodies from multiple B-cell lines, each recognising slightly different epitopes on the target, which can produce broader but less precise reactivity. A monoclonal test isolates one binding specificity, giving more reproducible and interpretable results between batches and laboratories.
Are monoclonal antibody tests used only for confirming human blood?+
No. While they are the basis of confirmatory human blood tests, the same monoclonal antibody principle underlies species-identification kits used in wildlife crime investigations and food fraud testing, wherever a specific protein marker needs to be detected with minimal cross-reaction to related species.
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...
- Lateral-Flow Immunoassay
- A point-of-care competitive immunochromatographic format on a nitrocellulose strip. In the absence of drug, colloidal gold-labelled antibody is captured at a test...
- Precipitin Test
- A serological method in which an antiserum specific to one species' proteins is mixed with an extract of an unknown specimen. Formation...
- ABO Blood Group System
- Classification of red blood cells by the presence or absence of A and B antigens on the cell membrane, determined by alleles...
- CITES
- The Convention on International Trade in Endangered Species of Wild Fauna and Flora, a multilateral treaty signed in 1973 now with over...
- ELISA (Enzyme-Linked Immunosorbent Assay)
- A plate-based immunoassay format in which a target antigen is captured by an antibody bound to a solid surface, detected by a...
- Enzyme-Linked Immunosorbent Assay (ELISA)
- An immunoassay format in which an enzyme-conjugated antibody produces a measurable colour change on substrate addition. Developed in 1971, adopted in forensic...
- HemaTrace ABAcard
- A lateral-flow device from Abacus Diagnostics that uses an anti-human haemoglobin monoclonal antibody. It is the most widely validated immunological blood confirmatory...
- Lateral-Flow Immunochromatographic Assay
- A rapid, single-use immunoassay format in which sample extract migrates along a nitrocellulose membrane past a detection zone loaded with antigen-specific antibody...
- Prozone (Hook) Effect
- A false-negative agglutination result caused by antibody excess. When antibody molecules outnumber antigen sites, each site is occupied by a single antibody...
- Radioimmunoassay (RIA)
- An immunological quantification method developed in the late 1950s in which a radiolabelled antigen competes with unlabelled antigen for antibody binding sites....
- RSID-Blood
- Rapid Stain Identification of Blood, a lateral-flow strip from Independent Forensics that also targets human haemoglobin. Functionally equivalent to HemaTrace in principle;...
Explained in these topics
- History of Forensic Serology and Immunological MethodsAn antibody produced by a single clone of hybridoma cells and therefore specific to a single epitope. Their availability from the 1975 Kohler-Milstein method t...
- Immunological Confirmatory Tests for Human BloodAn antibody produced from a single cloned B-cell line, so that every molecule in the preparation binds the same epitope with the same affinity. Monoclonal anti...
- Immunological Testing in Wildlife Crime and Food Fraud Investigations