I think I agree, Bill. From what I recall, CAP is more concerned with PATIENT results with old, new lots (no significant variation in result with either lot). I remember it being a pain with urine dipsticks doing lot to lot comparisons. If we don't get Fetalscreen tests for several days or a week, the samples are no longer "stable". Plus we hardly see positive fetal screens (maybe 2 a year). Thanks everyone for the input. Colleen Hinrichsen, MT (ASCP) SBB