Detect residual DNA from production organisms using sensitive, regulatory-aligned molecular methods.
Assessment of the presence of DNA in final products is performed to determine whether residual genetic material from the production organism is present. This is a key requirement for microbial-derived products. The objective is to demonstrate absence of detectable DNA within defined limits using sensitive and well-established molecular methods.
This service is intended for companies developing microbial products for food, feed, and industrial applications, particularly where regulatory frameworks such as EFSA require evidence that DNA from the production organism is not present in the final product. It is especially relevant for genetically modified production strains or when specific genetic elements of concern (e.g. acquired antimicrobial resistance genes) must be excluded from the final product.
DNA detection is performed using PCR-based methods targeting strain-specific or gene-specific sequences. A method development phase is typically included to optimise DNA extraction from the product matrix and to evaluate potential PCR inhibition. Detection limits are established using spiking studies across multiple batches, ensuring reliable sensitivity under realistic conditions. Appropriate positive and negative controls are included to verify assay performance.
Clients receive a comprehensive report including assay design, demonstration of method suitability (e.g. extraction efficiency and inhibition control), determination of detection limits, and test results. The report clearly states whether DNA was detected within defined limits and provides a regulatory interpretation aligned with EFSA expectations. All results are structured for direct inclusion in regulatory dossiers.
We define the detection strategy, including DNA extraction and selection of strain-specific PCR targets where required.
A spiking control is introduced into the product matrix to confirm DNA recovery and absence of PCR inhibition, ensuring that the method is suitable for the sample type.
Product samples are analysed using PCR-based methods under defined conditions validated within the study, including assessment of detection limits and matrix effects.
The limit of detection (LoD) is determined through additional spiking studies with lower DNA levels and replicate testing to establish the lowest detectable amount in the product matrix.
Results are interpreted within the validated detection limits and provided in a structured, regulatory-ready report aligned with EFSA expectations.
Detection limits determined through matrix-specific spiking studies
PCR-based methods capable of detecting residual DNA within defined detection limits
Optimised workflows to address inhibition in complex product matrices
Reports structured for direct inclusion in EFSA and global dossiers
Assessment of the presence of DNA is required to demonstrate that residual genetic material from the production organism is not detectable within defined limits. This is particularly important for genetically modified strains and for excluding genes of concern.
Residual DNA is typically detected using PCR-based methods targeting strain-specific or gene-specific sequences. These approaches provide high sensitivity and allow targeted assessment of relevant genetic elements.
The target gene is selected based on its specificity to the production strain and its regulatory relevance, often focusing on strain-specific sequences or genes of concern (e.g. AMR genes or introduced elements). Whole genome sequencing data are used to ensure specificity. In line with EFSA guidance, primers are designed to amplify short fragments (≤1 kb) to ensure detection of potentially fragmented DNA. Assay parameters are fully documented to ensure transparency and reproducibility.
The detection limit is determined using matrix-specific spiking studies in which known amounts of DNA are added to the product. This ensures that assay sensitivity reflects real product conditions, including potential inhibition effects.
“Absence of DNA” means that no DNA is detected above the validated detection limit of the method. Absolute absence cannot be proven, but results are interpreted within defined sensitivity thresholds accepted by regulatory authorities.
Identify genetic elements of concern, including AMR and toxin-related genes
Demonstrate absence of living production organisms using validated culture-based methods
Evaluate functional and toxigenic risks associated with microbial metabolites
Ensure your product meets regulatory expectations with a reliable DNA detection strategy. Our experts guide you through study design, execution, and interpretation to deliver dossier-ready results.
