CD Laboratory for Molecular Food Analytics

Nucleic acid-based methods for the quantification and characterisation of germs are being developed for use in food analysis. Thanks to their particularly high detection sensitivity, these methods will be able to identify pathogenic microorganisms with greater efficiency than before. The importance of such methods for the risk assessment of microbial hazards is also taken into account.

Before they can be identified, pathogenic microorganisms must be isolated from food. So-called enrichment media (germ cultures) are often used for this purpose. The need to cultivate the target germ for several days is an obvious disadvantage of such cultural detection methods. In addition, the original quantity of the target germ can no longer be quantified after this enrichment step. For this reason, methods for analysing food contamination are being developed that are based on molecular biological methods and allow direct quantification of the germ.

The challenge here is that each analysis method and each pathogen requires individual preparation of the test material. Special sample preparation techniques are developed for this purpose, which are combined with nucleic acid-based detection methods. These methods include the polymerase chain reaction (PCR) and microarrays.

PCR can be used to multiply the smallest amounts of genetic material (DNA) as required. Microarrays allow numerous single-gene analyses to be carried out on a carrier substance (chip) with the smallest quantities of biological sample material. All of these methods - individually or in combination - enable either the quantification or characterisation of the smallest traces of pathogenic organisms. These approaches are then validated in practice using new models.

The results of these research activities have a direct impact on risk assessment. Improved detection methods allow risks to be recognised quickly and the impact of contamination on food safety to be illustrated. Accordingly, part of the work involves integrating the optimised detection methods into risk assessments. The aim of the research is to facilitate the introduction of countermeasures through faster detection and characterisation of hazards.