Labeling Milk along Its Production Chain with DNA Encapsulated in Silica

Abstract

The capability of tracing a food product along its production chain is important to ensure food safety and product authenticity. For this purpose and as an application example, recently developed Silica Particles with Encapsulated DNA (SPED) were added to milk at concentrations ranging from 0.1 to 100 ppb (μg per kg milk). Thereby the milk, as well as the milk-derived products yoghurt and cheese, could be uniquely labeled with a DNA tag. Procedures for the extraction of the DNA tags from the food matrixes were elaborated and allowed identification and quantification of previously marked products by quantitative polymerase chain reaction (qPCR) with detection limits below 1 ppb of added particles. The applicability of synthetic as well as naturally occurring DNA sequences was shown. The usage of approved food additives as DNA carrier (silica = E551) and the low cost of the technology (<0.1 USD per ton of milk labeled with 10 ppb of SPED) display the technical applicability of this food labeling technology.

A vision for ubiquitous sequencing

“…Recent work has tested the usage of such tags in the food supply chain by delivering exogenous DNA fragments within a coat of silica, a common food additive, at an extremely low cost. It has been shown that these tags could be used to trace the source of milk in dairy products such as yogurt (Bloch et al 2014) and serve as a long-term authentication mark of premium olive oil (Puddu et al 2014). Moving forward, artificial DNA labels can create an edible data structure that includes the type of food, producer, lot number, nutrient information, and presence of known allergens or simply encode a URL to a webpage that contains this information.…”

DNA nanotechnology: new adventures for an old warhorse

“…One simple method would be through standardized watermarking of genetically engineered organisms [42,43]. Furthermore, DNA barcoding can serve as a valuable method for tracking food and agricultural products for authentication and safety concerns [44]. …”

Detecting and Number Counting of Single Engineered Nanoparticles by Digital Particle Polymerase Chain Reaction

“…In our previous work we have shown that silica particle detection is compatible with DNA, but accessible detection limits have been > 10'000 particles per analysis,15 still far away from the potential PCR analytics has to offer. To reach the goal of detecting single nanoparticles, we had to significantly improve the synthesis of DNA comprising particles to yield individual, non-agglomerated sub 100 nm particles.…”