Secretor Status
Definition
A genetic trait that determines whether a person expresses their ABO blood group antigens in secreted body fluids such as saliva, semen, and vaginal fluid, in addition to red blood cells. Approximately 80 percent of the population are secretors. Secretor status affects whether ABO typing can be performed on a body-fluid stain that contains no intact red blood cells.
- Secretors in population
- About 80 percent of people are secretors
- Fluids tested
- Saliva, semen, sweat, and other body fluids
- Genetic basis
- Dominant Se gene
Common questions
What is secretor status in forensic serology?+
Secretor status is whether a person secretes ABH blood-group antigens into body fluids like saliva and semen. About 80 percent of people are secretors. This matters in forensic investigation because it lets you test saliva or semen stains for blood group.
Why does secretor status matter when analyzing saliva or semen?+
Bloodstains contain blood-group antigens, but saliva and semen only contain them if the person is a secretor. The presence of these water-soluble antigens in those fluids depends on secretor status. Non-secretors will not show ABH antigens in saliva or semen, even though they have them in blood.
How is secretor status determined?+
Secretor status is determined through the Lewis blood-group system. A dominant Se gene controls whether a person secretes ABH antigens into body fluids.
Related terms
- Antigen
- A molecule recognised by the adaptive immune system through specific binding to an antibody or T-cell receptor. Defined by immunogenicity (capacity to...
- 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...
- 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 Transferase
- A glycosyltransferase enzyme encoded by the ABO gene on chromosome 9. The A allele encodes an enzyme that adds N-acetylgalactosamine to H...
- Absorption-Elution
- A technique for detecting antigens on dried red cell debris. Specific antiserum is absorbed onto the stain; if the antigen is present,...
- Absorption-Inhibition
- A known volume of antiserum is exposed to the stain; the residual unbound antibody is then titrated against indicator cells. A drop...
- Antibody (Immunoglobulin)
- A Y-shaped glycoprotein produced by B lymphocytes that binds a specific antigen at its variable regions. Antibodies used as forensic reagents are...
- Antibody (Isohaemagglutinin)
- An immunoglobulin in plasma directed against red-cell antigens the host does not carry. Group O serum carries anti-A and anti-B; group AB...
- Antiserum
- Serum collected from an immunised animal containing antibodies directed against a specific antigen or group of antigens. In species identification, antiserum raised...
- Bombay Phenotype (Oh)
- A rare phenotype in which individuals lack functional H antigen on red cells and in secretions due to mutations in FUT1 (and...
Explained in these topics
- The ABO Blood Group System: Genetics and SerologyWhether a person secretes ABO antigens in body fluids such as saliva and semen, determined by the FUT2 gene. Secretors (approximately 80 percent of most popula...
- Antigens: Structure, Types, and Forensic RelevanceA genetic trait that determines whether a person expresses their ABO blood group antigens in secreted body fluids such as saliva, semen, and vaginal fluid, in...
- Blood Group Systems in Forensic Science: ABO, Rh, MNS and BeyondDominant Se gene allows ABH antigens to be secreted in saliva, semen, sweat. About 80% of the Indian population are secretors; the rest are non-secretors. Test...
- Techniques for Determining Blood Groups from BloodstainsAbout 80 percent of people secrete water-soluble ABH antigens into saliva, semen and other body fluids. Grouping a saliva or semen stain depends on secretor st...
- The Role of Immunology in Forensic ScienceA heritable trait in which individuals (approximately 80 percent of most populations) secrete their ABO blood group antigens into body fluids including saliva,...
- Scope and History of Forensic SerologyAbout 80% of people secrete ABH blood-group antigens into body fluids such as saliva and semen. Secretor status was historically used to extend blood-group ana...
- The Transition from Serology to DNA Profiling in Forensic ScienceA genetically determined trait in which approximately 80 percent of the human population (secretors) express ABO blood group antigens in body fluids such as sa...