Glossary of Terms
A cheek swab used to obtain DNA samples from cheek cells. A buccal swab is performed by gently rubbing the inside of the cheek with a Q-tip-like swab. After the swabs arrive in DDC's laboratory, DNA samples are extracted from the swabs for analysis.
Chain of Custody
The chain of custody refers to the documentation process that assures the DNA samples collected from the tested parties were obtained by a neutral party, labeled properly, and delivered to the laboratory untampered. The chain of custody allows test results to be legally defensible in a court of law.
DNA Diagnostics Center
Deoxyribonucleic acid, the "building block of life" found inside the cell of every human being.
A DNA profile is a record of a person's combination of DNA markers. It also serves as a useful tool for genetic identification.
An exclusion result means that the DNA test has revealed non-matches in the DNA profiles of the tested parties, and the biological relationship being tested is excluded (e.g., the alleged father is not the biological father).
Mitochondrial DNA (mtDNA)
A type of DNA found in cells' mitochondria. mtDNA is passed maternally from a mother to her male and female offspring, and therefore mtDNA analysis can be used to ascertain whether two or more individuals share a maternal line.
A non-exclusion result means that the DNA test has revealed matches in the DNA profiles of the tested parties, providing evidence that a biological relationship exists among the tested parties (e.g., the alleged father is the biological father).
Paternity Index (PI)
Paternity Index is a numerical indication of the strength of the genetic evidence in a paternity test (the genetic odds in favor of paternity). The number generated indicates the number of times more likely the alleged father is the biological father of the child than a random man in the population. A PI is calculated for each locus, and its magnitude is dependent on how common or rare the shared allele is between the alleged father and child.
Probability of Paternity
The conversion of the Combined Paternity Index (CPI) to a percentage is termed the Probability of Paternity.