From Dr. Tang: Dear George, In the mixing test, commonly 20 healthy donors is required for preparing normal pooled plasma, why not 15, 10, or 5 donors? Have any studies validated that? Thank you for your reply.
Hello, Dr. Tang. I know of no published studies that establish 20 donors as a minimum for producing pooled normal plasma. The policy appears to be based on custom and expert opinion. I’ve invited some experts to comment, we may learn more in the next few days. Geo.
More: I just spoke with Larry Brace, PhD, who asserts that 20 data points provide statistical assurance that the pool results represent a true population sampling, and that this is a statistician’s convention. However, we don’t have access to authoritative references.