Do you need to verify your microbiological methods?

However, changes in the validation of microbiological methods, the approval of new standards such as ISO 16140-3, and recent modifications to the determination of uncertainty, mean that laboratories must quickly adapt how they validate their verification methods. Moreover, in microbiology, both sample analysis and uncertainty calculation present additional complexities compared to other types of samples. This is because samples, being a living organism, are neither homogeneous nor stable. This fact means that understanding the proper functioning of detection and quantification methods requires more effort and control after growth in a detector system under specific incubator conditions. This type of testing involves many factors, such as the physiological state of the microorganism itself, the distribution of the microorganism in the tested sample, the volume of dilution plated, incubation temperature and time, etc., all of which affect the final result. The quantification of variability contributed by each factor is complex. To implement these standards, laboratories performing microbiological tests must take all these factors into account in order to validate both detection and quantification methods through spreadsheets and procedures that guarantee the quality and reliability of your laboratory’s results. Laboratories must conduct validations following a documented procedure and apply the methodologies as necessary. To implement any of the techniques, calculations need to be performed to confirm that the required prerequisites are met, determining whether the validation is suitable for its intended purpose. The validation process often focuses on checking certain parameters like precision (in repeatability and/or reproducibility) and accuracy. Furthermore, another important requirement when performing calculations for a validation of a testing method, according to UNE-EN ISO/IEC 17025, is the determination of testing uncertainty. There are various methodologies for calculating it, some of which can be complex. For this reason, it is recommended that laboratories have a procedure and tools that simplify the evaluation process and minimize calculation errors. The results from experiments conducted during the validation allow, through comparison with the prerequisites, the declaration of the validation of the testing method and the establishment of acceptable values for quality control.