On a Method for Calculation and Analysis of Results in the McKenzie Assay for Thyrotropin (TSH). ∗

Summary

A new method to calculate and analyze results in the McKenzie assay for TSH is presented. It is proposed: 1) to transform the original data (radioactivity counts/ fixed volume/fixed time) in their logarithms (logo¹⁰); this applies to both first (control) and second (after TSH) blood samples; 2) a covariance analysis is then applied on the transformed data, the second blood values (dependent variable) being adjusted to the values of the first blood sample (independent variable). This method removes the heteroscedasticity inherent in the original calculations as proposed by McKenzie, thus increasing precision and reliability of the experiments.