DNA testing provides information about a person's genetic composition. There are two types of DNA, coding and non-coding, both of which provide information during the course of a DNA test. When DNA is tested, the correlation between the two types of DNA and the four bases of DNA (adenine, thymine, guanine and cytosine) are considered. Actual DNA sequencing is what a DNA test determines. This sequence varies from one person to another. The actual DNA test performed depends upon the purpose of the test, the amount of DNA material available and the quality of the DNA.
Restriction Fragment Length Polymorphism
One type of forensic DNA testing is restriction fragment length polymorphism (RFLP) testing. This form of DNA testing is an older form of DNA testing; however, it is sometimes the preferred test due to the accuracy of the results. RFLP requires a substantial amount of DNA in order to perform the test. Additionally, the DNA must be un-degraded, or in a near perfect condition. RFLP testing takes longer to perform than any other form of DNA testing.
Polymer Chain Reaction
Polymer chain reaction (PCR) testing is another form of forensic DNA testing. This type of testing is newer than RFLP testing. DNA used for this form of testing can be somewhat more degraded than DNA required for RFLP testing. Also, a smaller amount of DNA is required for PCR testing. While the results are generally available faster through PCR testing than RFLP testing, the PCR test is considered less accurate because contaminates from testing and/or the crime scene can affect the test results.
Genealogical
Genealogical DNA testing is the type of testing used to determine paternity. However, that isn't the only use of genealogical DNA testing. It can also be used to verify ancestry. This type of DNA testing usually involves the collection of DNA from cells inside the cheek. In some cases, genetic counselors may use genealogical DNA testing to determine the likelihood of a couple having a child with congenital birth defects.
