DNA paternity testing is based on the fact that each person's unique genetic blueprint is stored in material known as DNA. This DNA determines everything about us as human beings and is largely the same for all people. However, small differences in DNA between people determine each of our unique characteristics, including traits like eye color and blood type. There are also DNA differences that have no biological purpose, but which are useful for differentiating between or identifying people. Markers for identity applications like paternity testing or forensic identification use these types of non-functional genetic differences. One type of such markers are called Short Tandem Repeats (or STRs) because they have varying numbers of repeated segments of DNA. Another type are called Single Nucleotide Polymorphisms (or SNPs) because they have a variation in only a single DNA base.
Each person's DNA exists in two sets - one set of DNA is inherited from their mother and one from their father. If that portion of the child's DNA pattern that is not inherited from the mother (called the obligate paternal portion) does not match the DNA pattern of the alleged father, he is excluded as the biological father. Exclusion is verified by at least three DNA marker systems. If that portion of the child's DNA pattern that is not inherited from the mother is present in the alleged father's pattern, the alleged father cannot be excluded and is highly likely to be the biological father. A probability of paternity can be determined based on the frequency of the alleged father's matching DNA pattern in the population. The testing procedure is continued until a minimum probability of paternity of 99.99% is achieved. However, results are typically 99.99% or higher.
Orchid Cellmark is one of the world’s leading paternity testing providers, processing more than 100,000 cases each year. Our laboratories are fully accredited by the American Association of Blood Banks as well as numerous industry and government bodies. We use industry standard technology and state of the art instrumentation and automation to ensure the highest quality and consistency in testing results. The following is a brief summary of the testing process - these steps are also described in more detail under the Lab Tour section of this web-site.
Collection - Specimens are collected by swabbing cells from the inside of a person's cheek using sterile cotton swabs.
Shipping - Whether collected by a third party or using our convenient At Home testing kit, specimens are shipped in the supplied prepaid shipping materials to the laboratory.
Specimen Receipt - Once received at the laboratory, specimens are logged into the computerized tracking system and are immediately sent to the DNA testing laboratory for processing, usually within hours of receipt.
Testing - Specimens go through multiple standardized laboratory procedures, including isolation of DNA, amplification by Polymerase Chain Reaction, detection on automated DNA sequencing instrumentation, analysis by sophisticated computer software and trained analysts, and report generation.
Delivery of Results - A signed, notarized report of laboratory results and the conclusion is mailed to designated parties by first class mail.