Glossary of DNA Terms

Buccal Swab

Swab used to collect loose cheek cells from the inside of the mouth. It is often made from Dacron®, a polyester that provides a suitable surface to maintain DNA samples after collection.

Chromosome

Chromosomes are microscopic, thread-like parts of a cell, consisting mostly of DNA. Chromosomes carry hereditary information in the form of genes. Every species of animal has a specific number of chromosomes; humans have 46 total (23 pairs).

DNA

Deoxyribonucleic acid (DNA) is a complex organic compound found in all living cells. It is the chemical basis for genes. Its double helical structure comes from two strands wound around each other. DNA is in the nucleus of all cells (except red blood cells) and in the mitochondria.

Genes

A gene is a specific sequence in DNA located on a chromosome. Genes carry hereditary information and control transmission and expression of hereditary traits.

Maternal Lineage

Line of descent (inheritance) from a common female ancestor. Maternal lineages can be established through mtDNA testing.

Mitochondria

Often called the “power plant” of the cell, mitochondria are found in cells outside the nucleus, and they produce energy for the cell.

Paternal Lineage

Line of descent (inheritance) from a common male ancestor. Paternal lineages can be established through Y-STR testing.

Standard Trio

In DNA testing, a standard trio refers to a mother, father, and child.