Jhy-Jhu Lin
Amplified restriction fragment polymorphism (AFLP) is a PCRbased DNA fingerprinting technique. In AFLP analysis, bacterial genomic DNA is digested with restriction enzymes, ligated to adapters, and a subset of DNA fragments are amplified using primers containing 16 adapter defined sequences with one additional arbitrary nucleotide. Polymorphisms of different Escherichia coli strains or Agrobacterium tumefaciens strains were demonstrated as distinct, unique bands in a denaturing sequencing gel using AFLP. A novel PCR based plant molecular marker, amplified restriction fragment polymorphism (AFLP) overcomes many of the problems of RFLP and RAPD. AFLP has been used to establish genetic linkage maps and to localize disease resistant genes ( 3 , 4 ). There are three major steps in the AFLP procedure: (i) restriction endonuclease digestion of genomic DNA and the ligation of specific adapters; (ii) amplification of the restriction fragments by PCR using primer pairs containing common sequences of the adapter and one to three arbitrary nucleotides; (iii) analysis of the amplified fragments using gel electrophoresis. The combination of different restriction enzymes and the choice of selective nucleotides in the primers for PCR make AFLP a useful new system for molecular typing of microorganisms.