DNA Testing Resources
Overview
Non-standard samples
Chain of Custody
Results Interpretation
DNA 101
Overview
How is Nuclear DNA Organized?
Why is Autosomal DNA Ideal for Identity and Parentage Testing?
What is the basis for autosomal STR testing?
Steps in DNA Sample Processing
Raw STR Data
Interpreting STR Results in a Paternity Test
Y-STR Analysis
Mitochondrial DNA Analysis
DNA Glossary
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Find a Collection Center
Orchid utilizes a network of over 5000 collection sites worldwide.
Orchid utilizes a network of over 5000 collection sites worldwide.
Accreditations
Orchid Cellmark holds multiple accreditations from various organizations and adheres to the standards of each accrediting organization. Compliance by our laboratories to these accreditation requirements provides assurance to our clients that test results provided by Orchid Cellmark are of the highest quality. Clink on the links above to learn more about our accreditations.
Orchid Cellmark holds multiple accreditations from various organizations and adheres to the standards of each accrediting organization. Compliance by our laboratories to these accreditation requirements provides assurance to our clients that test results provided by Orchid Cellmark are of the highest quality. Clink on the links above to learn more about our accreditations.
DNA Testing Resources
DNA 101
How is Nuclear DNA Organized?
Chromosomes - DNA is contained in molecules known as chromosomes. Each individual has 46 total chromosomes or 23 pairs - one of each pair comes from each parent. 22 pairs of chromosomes contain what is called autosomal DNA and the 23rd pair contains DNA that determines the gender of the child. A male is XY and a female is XX. A routine parentage test examines non-coding regions of the autosomal DNA but also examines a section of the 23rd pair of chromosomes to determine if the tested individual is male or female. Our Y-STR test examines the DNA that is present on the Y-chromosome, which is present only in males.
Double Helix – On a more microscopic level, the chromosomes are actually made up of DNA that is present as a double-stranded molecule called a double helix.
Nucleotides - The DNA double helix is a long chain of molecules. Each molecule is formed from the nucleotides (bases) that are like letters of the alphabet. However while the English alphabet has 26 letters, the DNA alphabet has only four letters called nucleotides or bases:
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
The bases of the DNA pair with each other to form the double helix. Each DNA double helix has about 3 billion base pairs. When stretched out, it would be equivalent to 6 feet.
