The second type of test is called a RFLP analysis. RFLP stands for Restriction Fragment Length Polymorphism. This is a more traditional DNA test; the one usually used in crime labs to help identify suspects in a crime. This test requires a larger sample of DNA, and that usually takes the form of a blood draw. However, because of recent technology advances in DNA testing, a buccal swab sample has been used in RFLP analysis, and may become over time the preferred method for DNA paternity testing.