Definition of system suitability and proficiency testing acceptance criteria for the standardization of quality control methodologies of botanical bioactives: A case study for the development of AOAC Official Method of Analysis 2020.05 flavanols and procyanidins

Flavanols and procyanidins are bioactives found in many foods including cocoa. The characterization of cocoa flavanols and procyanidins (CF) has historically been challenged by the lack of commercially available standards and weak chromatographic separation performances. The recent release of a reference material and the final authorization of an AOAC Official Method of Analysis (AOAC 2020.05) technically enables the standardization of CF testing. However, the practical implementation of CF testing for routine testing remains challenging for new laboratories, highlighting the need to define guidelines and acceptance criteria to verify normal method performance and user proficiency. This study leveraged the data generated from the recent multi-laboratory validation to define normal method performances. While the challenges associated with HILIC separation can be alleviated through a thorough system equilibration, monitoring system performances remains critical to routine operation and a laboratory's ability to generate reliable data. Guidelines for routine analysis were developed for system precision and bracketing standard recovery, as well as acceptance criteria for the analysis of the reference material. These guidelines not only complete a body of work that provide accessible, reliable, and robust CF analysis solution to research and quality laboratories, but also provide an example to facilitate the establishment and implementation of future international testing standards for botanical bioactives.

Reverse Transcription-Quantitative Real-Time Polymerase Chain Reaction (RT-qPCR) for Gene Expression Analyses

The reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) is considered to be the gold standard for gene expression research. However, for this claim to be valid, RT-qPCR studies must test and optimize the quality of its RNA templates and assays. This chapter describes the experimental procedures required to generate reliable and reproducible gene expression results using RT-qPCR.