Probability of Exclusion
Definition
The proportion of the population whose blood type differs from that of the stain and who would therefore be excluded as its source. A higher probability of exclusion means the typing result is more discriminating.
- Field
- Blood group serology
- Measures
- Discriminating power of a typing system
- Direction
- Higher value = more discriminating
- Complement
- Probability of inclusion
Common questions
How does probability of exclusion differ from a match probability?+
A match probability describes how rare a specific observed genotype or phenotype is in the population, while probability of exclusion describes, before any specific result is known, what fraction of the population a typing system can rule out on average, a general measure of the system's discriminating power.
Why do minor blood group systems have lower probability of exclusion than DNA profiling?+
Minor blood group systems like MNS, Kell, and Duffy have relatively few common alleles, so most individuals share the same phenotype, giving a low probability of exclusion compared with the many independent, highly polymorphic STR loci used in DNA profiling.
Related terms
- Absorption-Elution
- A technique for detecting antigens on dried red cell debris. Specific antiserum is absorbed onto the stain; if the antigen is present,...
- Antiserum
- Serum collected from an immunised animal containing antibodies directed against a specific antigen or group of antigens. In species identification, antiserum raised...
- Blood Group System
- A set of red cell surface antigens encoded by one gene locus or by two tightly linked loci. The International Society of...
- Linkage Disequilibrium
- The non-random association of alleles at different loci within a population. Certain HLA allele combinations (e.g., HLA-A1 with HLA-B8 with HLA-DR3) occur...
- Phenotype Frequency
- The proportion of a given population that expresses a particular antigen combination. Multiplying phenotype frequencies across independent loci gives the combined frequency...