Accuracy and precision of serum gastrin measurements in commercial laboratories.

Patients referred to us with "positive" secretin tests and the diagnosis of Zollinger-Ellison syndrome were found to be achlorhydric. This observation led us to study prospectively the accuracy and precision of serum gastrin determinations from commercial laboratories. Synthetic gastrin (G17) was added to serum to achieve gastrin concentrations of 50, 100, 250, 500, 750, 1000, 3000, and 5000 pg/mL after subtraction of the basal value (24 pg/mL).