An optimized design for the establishment of assigned values in control sera. The establishment of assigned values in...

From the study described in part 1 of this series (Passing, H. et al. (1981), this j. 19, 1137-1144) it has been derived in part 3 (Passing, H. (1981), this j. 19, 1153--1166) that 6 reference laboratories are appropriate for the establishment of assigned values and their uncertainty intervals in a control serum. From the same study the two outstanding characteristics of an optimized design are found: It is sufficient that each reference laboratory performs single determinations within independent series. The number of series however has no relevant influence on accuracy and precision of the assigned values. The following design is obtained: Six reference laboratories perform single determinations in five independent series each. Additionally, the complete concept of establishment of assigned values is summarized. Up to now, the model has met the expectations in practice.