How is DNA testing performed?
A. The technology we use most often is PCR or polymerase chain reaction testing. First we isolate pure DNA from the specimen (a cheek swab, blood, or hair sample) by removing all the proteins and other things that can be found within a cell. The DNA is then placed into a thermocycler along with fluorescent primers for specific “loci” or locations on the DNA which enable the system to locate specific fragments of DNA. The thermocycler is set to cycle through a certain number of temperature cycles. Throughout the cycles, the primer finds specific areas within the DNA that are repeated and amplifies those areas. After the DNA has been amplified, it is place in an ABI Prism Genetic Analyzer for capillary electrophoresis. In this process, the DNA loci are mapped and data on each is collected. This results in a comprehensive “profile” of each individual. These individual profiles are then reviewed by a trained, experienced Ph.D.
