CHAPTER 9: A Perspective on Quantitative DNA Approaches

To combat food fraud, accurate quantitative analytical methods are required. Method validation helps qualify a method as fit for purpose through the objective evaluation of performance characteristics, and a measurement uncertainty estimate associated with a result describes a range in which the true value is thought to lie. Through careful choice of DNA target, the robustness of a quantitative estimate can be ensured, even in the presence of mixed sample types and processed food materials. This chapter explores some of the uses and applications of DNA-based methods for accurate quantitation of species in food samples and how these methods can be applied to compliance testing to differentiate between adventitious contamination and deliberate adulteration. It also provides additional guidance supporting polymerase chain reaction (PCR)-based approaches through using acceptance criteria and performance requirements already in the public domain to demonstrate a method's fitness for purpose.