A sequence change can create a restriction-enzyme recognition site, eliminate an existing site, or modify the distance between two sites. Each outcome changes which DNA segments are released during digestion and therefore changes their lengths. Comparing these length patterns allows researchers to detect sequence variation even when they are not directly determining the entire DNA sequence.
Restriction enzymes cut at particular recognition sequences, so the spacing of those sequences determines the length of the intervening DNA fragment. A variant that leaves both recognition sites intact can still produce a different pattern if it changes the distance between them. This makes fragment size informative about structural differences within a genomic region.
An RFLP marker provides a detectable DNA pattern that can be compared among individuals or organisms alongside inherited traits. When a fragment pattern is associated with a trait through genetic comparisons, it can help investigators locate the trait-related region and study linkage. The approach therefore connects observable fragment differences with patterns of inheritance.
The workflow begins with DNA from the individuals or organisms being compared. A restriction enzyme cuts the DNA at its recognition sequences, producing fragments whose lengths reflect the underlying sequence arrangement. The fragments are then separated by gel electrophoresis, and the resulting patterns are examined to identify differences between samples.
Interpretation focuses on whether samples contain fragments of matching or different lengths. A changed pattern indicates that the DNA differs in a way that affects a cutting site or the spacing between sites. Researchers can then compare these patterns across samples to identify genetic variation relevant to mapping, linkage, or variant detection.
RFLP analysis has been used for gene mapping, linkage studies, detection of disease-associated variants, and DNA identification. Its value comes from converting sequence differences into observable fragment patterns that can be compared among samples. Although faster, high-throughput methods have largely replaced it, RFLP remains important as a foundational strategy in molecular genetics.