dna Glossary



Formerly known as the American Association of Blood Banks, an organization that sets standards for blood transfusion and related biological therapies, including DNA testing for identity verification


Evidence that is acceptable in a court of law.


Evidence that is acceptable in a court of law.


One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Alleged Father:

A man who is believed to be the biological father of a child, but has not yet been legally determined as such.


Any chromosome that is not a sex chromosome. Humans have 22 pairs of autosomes.


Relating to the relationship between a niece or nephew and their aunt or uncle.

Biological Child:

A child who is genetically related to both parents

Biological Father:

The man from whom a child has inherited half of its DNA and who is the genetic father of the child.

Buccal Swab:

A method for collecting DNA from the cells on the inside of a person’s cheek.

Chain of Custody:

The documented and unbroken transfer of evidence from the time it is collected until it is presented in court, ensuring its integrity.

Child Support:

Money paid by a non-custodial parent to the custodial parent to contribute to the expenses of raising their child.


Structures made of DNA and protein found in the nuclei of cells that carry genetic information.

Collection Facility:

A designated place where DNA samples are collected for testing.

Custodial Parent:

The parent with whom a child lives and who has primary care, custody, and responsibility for the child.

DNA Extraction:

The process of separating DNA from cells or viruses to study it more closely.

DNA Profile:

A unique pattern of DNA characteristics that can be used to identify an individual.

Dizygotic Twin:

Also known as fraternal twins, these are siblings who have developed from two different eggs fertilized by two different sperm, sharing 50% of their DNA.


In DNA testing, the determination that a person is not the biological parent or relative of another person.

Fraternal Twin:

Twins that are dizygotic, meaning they are the result of the fertilization of two separate eggs by two separate sperm.


A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.


The parent of one’s father or mother; a person’s grandmother or grandfather.

I-130 RFE:

I-130 Request for Evidence.” It is a notification that the United States Citizenship and Immigration Services (USCIS) sends to an applicant when additional evidence or documentation is required to process their I-130 Petition for Alien Relative.


In DNA testing, the determination that a person is the biological parent or relative of another person.


The state of being related to others by blood or family ties.


(plural of locus) – Specific, fixed positions on chromosomes where genes or genetic markers are located.


Relating to a mother; of or inherited from one’s mother.


Tracing descent through the maternal line.

Mitochondrial DNA:

The small circular chromosome found inside mitochondria, which are organelles located in the cytoplasm of eukaryotic cells. It is passed down from mothers to their offspring.


The smallest particle of a substance that retains the chemical properties of that substance, consisting of one or more atoms.


Refers to a parent who does not have primary custody of a child.


Paternity refers to the legal and biological relationship between a father and his child.

Paternity Attorney:

Is a lawyer who specializes in legal matters related to establishing or disproving paternity, which is the legal determination of who a child’s father is.

The main roles and responsibilities of a paternity attorney include:

  1. Paternity establishment
  2. Paternity disestablishment
  3. Child support
  4. Custody and visitation
  5. Adoption proceedings
  6. Legal advice

Paternity Estoppel:

Paternity by estoppel refers to a legal doctrine where a man may be considered the legal father of a child, even if he is not the biological father, due to his actions or conduct that led the child to believe he was their father.

Paternity Index (PI):

is a statistical measure used in genetic testing to evaluate the probability of paternity.

It compares the likelihood that the alleged father has contributed a particular allele (version of a gene) to a child versus the likelihood that a randomly selected unrelated man from the same population could have contributed the same allele.

Probability of Paternity:

The probability of paternity is a measure used in genetic testing to determine the likelihood that a man is the biological father of a child. It is calculated based on the comparison of DNA profiles between the alleged father, the child, and the mother (if available).

Random Man:

In the context of paternity testing, a man with no alleged or presumed biological relationship to a child.


A person connected by blood or marriage to another person.

Self Collection:

The process of an individual collecting their own biological samples, such as DNA via a buccal swab, often for genetic testing.

Sex Chromosome:

A type of chromosome involved in the determination of the sex and the development of sexual characteristics. In humans, these are the X and Y chromosomes.


A brother or sister; someone who shares at least one parent with another person.

Statistical Calculation:

statistical calculation refers to the use of statistical methods and techniques to analyze and interpret genetic data. It involves applying mathematical models and probability theory to study patterns, relationships, and variations in DNA sequences.

STR (Short Tandem Random):

Short tandem repeats are sequences of DNA bases that are repeated multiple times in a row. They are commonly used in DNA testing because they vary widely between individuals, making them useful for identification and relationship testing.


The degree of similarity of the alleles for a trait in an organism. For example, monozygotic twins have identical alleles for all their genes, while dizygotic twins do not.