Table 1.
(1) Preliminary development | (2) Feasibility experiments | (3) Internal validation | (4) External validation | |
---|---|---|---|---|
Method Goal | Method designed/ modified and method performance solidly understood | Scientifically sound, repeatable and efficient method | Minimally validated method | Fully validated method |
Analytic Goals |
• Build robustness into the method • Ensure repeatable and reliable data generation |
Establish results for appropriate validation elements |
• Limited method comparison in a single site • Defined method performance characteristics at a single site |
• Extensive evaluation of method in multiple sites • Defined method performance characteristics at several sites |
Documentation Requirements/Output |
Initial method validation study protocol • Define the design, application, purpose, and scope of the method • Define the endpoint(s) • Define the analytical requirements (performance parameters and acceptance criteria) • Define testing conditions • Define controls • Select comparator method (where applicable) • Conduct baseline experiments |
Draft SOP for the method • Define the final endpoint (s) for validation • Define strains for validation • Define testing conditions for conduct of validation • Propose a suitable experimental design for validation (sample size, testing pattern, and testing period as necessary) • Verify relevant performance characteristics (compare performance parameters results to the pre-specified acceptance criteria) |
Internal validation protocol and SOP for the method • Analytical requirements stated • Method claim drafted • Identify laboratories/sites for external validation • Compile a data package |
External validation protocol and report with the method ‘fitness for purpose’ statement • Method final claim produced • Analytical requirements stated • Implementation can be recommended |