Paternity testing glossary
Plain-English definitions for every term you'll see on a paternity test report or in the lab literature.
AABB Accreditation
The gold-standard accreditation for U.S. paternity labs, required by every U.S. court.
STR Marker
Short Tandem Repeat — a repeating DNA sequence used to identify individuals.
34-Marker Paternity Test
Our standard test reads 34 STR markers — nearly double the industry minimum.
Combined Paternity Index (CPI)
A statistical multiplier expressing how much more likely the alleged father is the biological father than a random man.
Probability of Paternity
The final percentage on a paternity report — usually 99.99%+ (inclusion) or 0% (exclusion).
Chain of Custody
Documented, tamper-evident tracking of DNA samples from collection to lab.
Buccal Swab
A soft swab that collects DNA-containing cells from the inside of your cheek.
Cheek Swab
The everyday name for a buccal swab — the standard DNA collection method.
Non-Invasive Prenatal Paternity (NIPP)
Paternity testing before birth using fetal DNA from the mother's blood.
Cell-Free Fetal DNA (cffDNA)
Fragments of fetal DNA that circulate in the pregnant mother's bloodstream.
Amniocentesis
An older invasive prenatal DNA sampling method with a small miscarriage risk.
Chorionic Villus Sampling (CVS)
An older invasive prenatal DNA sampling method performed 10–13 weeks.
USCIS Genetic Testing
The USCIS process for using DNA evidence in a family-based petition.
Form I-130
USCIS petition for an alien relative — often paired with DNA evidence.
Legal Paternity Test
A chain-of-custody DNA test admissible in court, immigration, and government proceedings.
Home Paternity Test
A DNA paternity test collected at home for personal knowledge — not court-admissible.
How It Works
Order → kit ships → swab → mail back → results in about a week.
CLIA Certification
The U.S. federal quality standard for clinical laboratories.
ISO/IEC 17025
International standard for lab testing and calibration competence.
College of American Pathologists (CAP)
Proficiency-testing program that validates lab accuracy.
34 vs 16 Markers
More markers = more certainty. Our 34-marker test is 2x the industry minimum.
Exclusion Result
A 0% probability of paternity — mathematically definitive.
Inclusion Result
A 99.99%+ probability of paternity — the alleged father is confirmed as the biological father.
Mother-Optional Testing
Modern paternity tests are conclusive without the mother's sample.
Prenatal Testing Window
Non-invasive prenatal paternity is available from 7 weeks of gestation until birth.
Grandparent DNA Test
Tests one or both paternal grandparents when the alleged father is unavailable.
Sibling DNA Test
Determines full-sibling, half-sibling, or unrelated relationships.
Avuncular (Aunt/Uncle) DNA Test
Tests a paternal aunt or uncle when the alleged father is unavailable.
Y-STR Testing
Analyzes short tandem repeats on the Y chromosome — passed unchanged father-to-son.
Mitochondrial DNA (mtDNA)
DNA passed from mother to all children — used for maternal-line questions.
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