Optimization of random amplification of polymorphic DNA analysis for molecular subtyping of Escherichia coli O157

Random amplification of polymorphic DNA (RAPD) analysis using the polymeras e chain reaction has proved to be a useful technique in the epidemiological investigation of micro-organisms but may suffer from a lack of reproducibi lity in poorly optimized protocols. In this study a method of obtaining rep roducible genomic fingerprints using RAPD analysis of Escherichia coli O157 is described. By systematic optimization of reaction conditions and select ion of suitable primers, reproducible and discriminatory profiles could be obtained from all E. coli O157 strains tested. In addition, two other metho ds of obtaining reproducible profiles from E. coli O157 strains without the need to purify genomic DNA are described.