UTILIZATION OF NYLON MEMBRANES FOR THE SP ECIFIED ISOLATION AND CHARACTERIZATION OF VEROTOXIN-PRODUCING ESCHERICHIA-COLI BY USING DNA-PROBES

A method for specific isolation of VT+-strains in raw milk is given. D NA-hybridization technique with DIG-labeled PCR-amplificates as probes are the basis. No background is seen by using ''DIG Easy Hyb'' soluti on and nylon membranes for colony- and plaque-hybridization (Boehringe r Mannheim GmbH). Marked colonies are visible on the membranes after d etection. So it is possible to select these colonies from a masterplat e. The results are available within one day (without enrichment and me mbrane preparation). After stripping the membranes can be used for a n ew hybridisation to detect another factor of virulence.