Best Practices in Assay Validation

Flow cytometry is a well-established approach used in numerous clinical assays across the globe. But like most assays used in a clinical setting, flow cytometry assays typically need to be validated before they can be used for diagnostic or clinical research purposes.

Assay validation is done to demonstrate that a 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, flow cytometry assays need to meet specific analytical method validation criteria. A validated assay can then be used in situations requiring GLP/GCP (good laboratory/clinical practice) compliance, like a clinical trial or routine diagnostic test.

Interested in the nuts and bolts of flow cytometry assay validation? Validation is usually what follows assay development. Validation is done to confirm that the method is fit for its intended use and the assay meets specific criteria with respect to stability requirements, accuracy, precision, specificity, detection limit, limit of quantitation, linearity and range, ruggedness, and robustness.

Flow cytometry assay validation can be done in as little as two to four weeks for a simple multicolor assay or up three months for a more complex assay. If you are doing work that requires assay validation, you should spend time working with experts in validation as you plan your validation process. You may also need input from regulatory experts to make sure you are examining all the right criteria. Validation involves extensive documentation, so this is something else you’ll need to plan for and consider.  In some situations, you may need to carry out inter-assay and inter-laboratory assessments of reproducibility and robustness.

So, venture fearlessly into validation and take your assay to the next level.