In [[molecular biology]], '''restriction fragment length polymorphism''', or RFLP (commonly pronounced “rif-lip”), is a technique that exploits variations in homologous DNA sequences. It refers to a [[polymorphism (biology)|difference]] between samples of [[Homology (biology)|homologous]] [[DNA]] molecules that come from differing locations of [[restriction site|restriction enzyme sites]], and to a related laboratory technique by which these segments can be illustrated. In '''RFLP analysis''', the DNA sample is broken into pieces (digested) by [[restriction enzymes]] and the resulting ''restriction fragments'' are separated according to their lengths by [[gel electrophoresis]]. Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first [[DNA profiling]] technique inexpensive enough to see widespread application. RFLP analysis was an important tool in [[genome mapping]], localization of genes for [[genetic disorder]]s, determination of [[Genetic testing|risk]] for disease, and [[paternity testing]].
