The pre-enrichment (or primary enrichment) and selective enrichment (or secondary enrichment) processes up to more than 32 hours. Hence, safe and efficient culture media preparation is an important part of cell and microorganism sample growth in the lab. To help ensure that the quality control of culture media in a microbiology laboratory can be performed accurately and quickly, DKSH offers ready-to use culture medias for Salmonella and Listeria detection.

This technology is based on soluble colorless molecules called chromogens, composed of a substrate targeting a specific enzymatic activity and a chromophore. When the target organism’s enzyme cleaves the colorless chromogenic conjugate, the chromophore is released. In its unconjugated form, the chromophore exhibits its distinctive color and forms a precipitate due to reduced solubility.

Scientists have developed nucleic acid-based methods for detection and identification of specific DNA or RNA sequence of the target pathogen. Detection of a target nucleic acid sequence is performed by simple polymerase chain reaction (PCR), hybridization probes, or primers. Nucleic-acid based methods detect specific genes in the target pathogens associated with seafood.

Real-time PCR combines the specificity of conventional PCR with the quantitative measurement of fluorescence for monitoring amplification of specific genes in the target pathogens. A number of qPCR schemes have been designed to detect target genes such as the cholera toxin gene (ctxA) of V. cholerae or the tdh/trh genes of V. parahaemolyticus in fish and crustacean samples. Detection of multiple target genes of different species, serotype, or subtypes can be done in a single reaction by multiplex assay.