Did you know that if you had a spinal tap for a cerebrospinal fluid-based Alzheimer's diagnosis in Boston, Stockholm, London, or San Diego, the readout would likely be different in each place? And different again this year and next? That's a problem for observational studies, drug trials, and multicenter research efforts on the earliest stages of AD. Aware of the issue, research leaders have organized. They now offer to academic and pharmaceutical sites around the world a standardized protocol and an ongoing Quality Control (QC) program. Pooled CSF reference samples made from surplus CSF taken in Swedish medical practice make it possible. It's free of charge.