Venturing into Flow Cytometry Assay Development and Assay Validation
Flow cytometry is a technology that enables multi-parametric analysis of thousands of cells per second and helps to identify and functionally characterize complex cell populations of interest, and is often used in discovery research, pre-clinical and clinical trials. Flow cytometric based methods can be challenging to develop and validate, given the number of cellular measurements involved and the lack of standardized cellular reference materials. The first step begins at project inception, where it is necessary to understand the application of the assay being developed so that it can be designed accordingly. Many aspects are considered during flow cytometry assay development, such as types of samples to be run, panel composition and the gating strategy for analysis. It is critical to understand the application of the assay when designing a robust flow cytometry validation process, including for example the adoption of GLP or GCP (Good Laboratory/Good Clinical Practice) guidelines and principals. Like most assays that are used in a clinical setting, developed flow cytometric assays typically need to be validated before they can be used for diagnostic or clinical research purposes.
Assay validation is performed to demonstrate that the method is accurate, specific, reproducible and robust over a designated range of measurement. Flow cytometry is considered an analytical method, and according to the FDA, developed flow cytometric assays need to meet specific analytical method validation criteria. A validated assay can then be used in situations requiring GLP &/or GCP compliance, such as within toxicology studies and clinical trials.
Interested in taking your assay to the next level? Validation is typically the next step following assay development. Validation is performed to confirm that the method is fit for its intended use and that the assay meets specific criteria with respect to stability requirements, accuracy, precision, specificity, detection limits, limit of quantitation, linearity, range and robustness. If you are performing work that requires assay validation, you should spend time working with experts in validation to help plan your validation process.