ABSTRACT
Restriction fragment length polymorphisms (RFLPs) have been shown to be good markers of taxonomic relatedness in a number of groups of organisms. The method is relatively simple and can be performed by anyone familiar with basic molecular biology techniques. DNA is prepared by a simple lysis procedure, subsequent removal of proteins by organic extraction, and purification on a cesium chloride density gradient. The DNA is digested with restriction endonucleases, the fragments separated electrophoretically on agarose gels, and transferred to nylon membranes by Southern blotting. Although it is sometimes easy to group small numbers of organisms by visual comparison of the RFLP patterns, larger numbers may require a more detailed analysis. Phylogenetic analysis may be performed using either parsimony or distance methods.
