Currently, definitive diagnoses of Creutzfeldt-Jakob disease (CJD) require an examination of the brains of deceased patients. In cooperation with an international consortium, Canada's National Microbiology Laboratory is performing a validation of a new test that can diagnose CJD in living patients. This test, the real-time quaking-induced conversion (RT-QuIC) assay, directly detects the disease associated form of the prion protein in cerebrospinal fluid. If validated, RT-QuIC will represent a major advance in the diagnoses of patients suspected to have CJD.