Forensic serology
Definition
The branch of forensic science concerned with detecting and characterising biological fluids (blood, semen, saliva, vaginal secretions) as evidence in legal proceedings, using chemical, immunological, and microscopic methods.
- Fluids tested
- Blood, semen, saliva, vaginal secretions
- Methods used
- Chemical, immunological, and microscopic analysis
- Primary purpose
- Identification and typing of biological evidence for legal proceedings
Common questions
What biological fluids can be tested in forensic serology?+
Forensic serology examines blood, semen, saliva, and vaginal secretions recovered from crime scenes. Technicians use chemical, immunological, and microscopic methods to detect and identify these fluids as evidence.
How is forensic serology different from DNA profiling?+
Forensic serology focuses on identifying and typing biological fluids themselves using traditional immunological and chemical techniques. It determines what fluid is present, where it came from, and its characteristics. DNA analysis, by contrast, extracts and compares genetic codes from those fluids to identify individuals.
Why was the ABO system important in forensic serology?+
The ABO system was historically a key method for typing blood and other body fluids before modern DNA technology. It allowed forensic scientists to narrow suspect lists and exclude individuals based on blood type grouping.
Related terms
- ABO system
- The blood-group classification described by Karl Landsteiner in 1901: groups A, B, AB, and O, defined by antigens on red-cell surfaces and...
- Agglutination
- Clumping of red cells that occurs when antibodies in serum bind to incompatible antigens on the cell surface, cross-linking cells into visible...
- Antigen
- A surface molecule that the immune system can recognise and respond to. On red blood cells, ABO antigens are oligosaccharide chains attached...
- Glycosyltransferase
- The enzyme encoded by the ABO gene locus that attaches terminal sugar residues to the H antigen chain. Group A transferase adds...
- H antigen
- The core fucosylated precursor oligosaccharide from which A and B antigens are biochemically constructed by glycosyltransferase enzymes. Group O individuals retain abundant...
- Isohemagglutinins
- The naturally occurring antibodies (anti-A and/or anti-B) present in serum from birth without prior transfusion or immunisation. Group A individuals carry anti-B;...
- Lateral-flow immunoassay
- A rapid, card-based test in which a stain extract wicks through a membrane past antibody-conjugate zones; a visible line forms within minutes...
- Precipitin test
- A species-confirmation test that adds species-specific antiserum to a stain extract; a visible precipitate forms only when the target protein is present....
- Presumptive test
- A fast, low-cost, class-specific screen used to triage a caseload before instrumental work begins. Examples are Marquis reagent for opioids and amphetamines,...
- Secretor status
- About 80% of people secrete ABH blood-group antigens into body fluids such as saliva and semen. Secretor status was historically used to...
Explained in these topics
- ABO System: Biology and Forensic HistoryThe branch of forensic biology focused on the identification, species determination, and typing of body fluids (blood, semen, saliva) recovered from crime scen...
- Scope and History of Forensic SerologyThe branch of forensic science concerned with detecting and characterising biological fluids (blood, semen, saliva, vaginal secretions) as evidence in legal pr...