Analytical evaluation of the CK-MB mass assay on the Technicon Immuno 1® system

Objectives: To evaluate the performance of the Technicon Immuno 1® CK-MB mass assay. Design and Methods: The precision was measured using the Bio-Rad Liquichek™ CK-MB controls and the Technicon Immuno 1® SETpoint CK-MB calibrators. The linearity was verified by diluting 9 patient serum samples containing high CK-MB concentrations, and the minimum detectable concentration determined by repetitive analysis of the zero calibrator. The assay was compared with the Johnson & Johnson Vitros® CK-MB activity assay using 111 patient serum samples. The reference range was determined using serum samples from 100 healthy adult volunteers. Results: The assay shows within-run CVs varying from 1.5 to 7.5% and between-day CVs from 1.5 to 4.8% for CK-MB concentrations ranging from 3.9 to 99.0 μg/L. The linearity study gave correlation coefficients greater than 0.9961. There was a very good correlation between mass and activity assays (r = 0.985). The reference values were estimated at 0.0–4.2 μg/L and the minimum detectable concentration at 0.5 μg/L. Conclusions: The evaluation shows that the Technicon Immuno 1® CK-MB mass assay has the analytical characteristics suitable for its inclusion in the modern clinical repertoire.