A DNA laboratory is a laboratory which specializes in conducting tests on DNA, the blueprint of life found in every cell of living organisms. These labs can extract DNA from samples, not always an easy task, and run tests to sequence the DNA. These tests may look for specific genetic markers, or be more general in nature, depending on the reason the test was ordered. Sending materials to a DNA laboratory can be very expensive, and the process of testing can be very time-consuming, contrary to the expectations of some who watch television shows in which DNA tests are completed in under an hour.
Getting DNA out of a sample can be very difficult. Some samples, like hair and blood, are easier to work with than others, but DNA labs can get intact material from surprising places, including the bone marrow of a skeleton, or scrapings of biological materials from a crime scene. It's important to handle the sample properly to avoid contamination, with contamination from the laboratory technician being a major concern. Assuming that a lab finds testable DNA, there may only be enough for one test, and it is possible that the evidence may be destroyed in the process of testing, which can be an issue with criminal cases.
Facilities at a DNA laboratory include a variety of types of equipment which can be used to sequence DNA. During the DNA sequencing process, specific areas of interest in the DNA are broken down to find their sequence of amino acids. This sequence can act like a fingerprint, linking a person to evidence, showing a genetic relationship between two individuals, or revealing information about someone's racial or ethnic origin. DNA sequencing can also be used to look for problem genes which cause defects, as may be done in genetic testing to determine whether or not parents carry harmful genes.
After material has been analyzed at a DNA laboratory, a written report is prepared to discuss the findings and their relevance. The report also usually discloses how reliable and helpful the findings are. For example, genetic testing may reveal weak evidence of a genetic connection between two people, or very strong evidence, and the strength of this evidence could be an important factor in evaluating how useful the evidence is. The lab will also discuss the methods used to sequence the DNA, so that the results can be critically examined and possibly replicated by another DNA laboratory.
Almost all DNA laboratories can conduct nuclear DNA testing, in which the nucleus of a living cell is used to gather DNA. Some perform mitochondrial DNA testing (mtDNA), looking for the maternally inherited genetic material in cell organelles known as mitochrondria. mtDNA can reveal genetic relationships along with other interesting information. Y-STR sequencing, in which the Y chromosome found in men is examined, is another service which may be offered at a DNA laboratory.