Multicenter validation study of two blockcycler- and one capillary-based real-time PCR methods for the detection of Salmonella in milk powder

A collaborative study including 13 German laboratories was conducted to evaluate the performance of two non-patented real-time PCR methods for the detection of Salmonella in milk powder targeting the ttrC/ttrA- or the invA gene. The enrichment procedure and sample DNA preparation method prior to the real-time PCR was the same for both systems and the identical DNA extraction samples were analysed. The traditional cultural method according to EN ISO 6579:2002 for the detection of Salmonella in food was performed in each laboratory as the reference. The participants received twelve coded milk powder samples each of 25 g for the analysis. Four of them were Salmonella negative (level L0), four artificially contaminated with