Validity of methodsExperiments were carried out In which it was assessed which Salmonella isolation method is the most productive one In the examination of broiler carcasses. Refrigerated, refrigerated and radiated (2.50 kGy), frozen and frozen and radiated (2.50 kGy) samples of broilers were examined. After evaluation of all results It was concluded that the following method was the most productive one:1. pre-enrichment in buffered peptone water at 37 °C for 20 hours2. enrichment in selenite cystine broth at 37 °C and at 43 °C for 24 hours3. selective plating on brilliant green sulphapyridine agar and XLD- agar at 37 °C for 24 hoursFrom this study It could not be concluded that other methods were not sufficiently reliable to be applied in other situations.However, it became clear that when sublethally damaged salmonellae are expected to be present, and when, as a result of the treatment, a different competitive microflora is present, adapted isolation methods should be used.The method chosen for Salmonella -isolation in the experiments described in this thesis was the ISO 3565/1975 reference method for isolation of salmonellae from meat and meat products. This method was ultimately preferred because of the experience obtained for many years in routine analyses.In two Instances other conditions than prescribed by the ISO-method were used; i.e. the samples were incubated at 37 °C or 43°C for 24 hours. The ISO-method as well as its slight modification proved to be reliable methods in the experiments reported.Escherichia coli versus Salmonella.The experiments have shown that the Escherichia coli K12 NDA strain tested can not be used as index microorganism for Salmonella : in this case Salmonella niloese and Salmonella panama on broilers, though in liquid and solid culture media the D 10 -values of these three microorganisms were similar.The experiments with pure cultures and with artificially contaminated carcasses showed that the following factors influenced D 10 -values:1. the culture media used before, during ...