Manual Procedure for Direct Microassay of Serum Glucose by Use of o-Toluidine, and Its Adaptation to the SMA 12/60 AutoAnalyzer

A direct o-toluidine method for serum glucose is described as an alternative to the usual Cu—neocuproine method used with the Technicon SMA 12/60 AutoAnalyzer. Routine operation of the machine is simplified: the number of reagents and manifold lines is decreased and the dialyzer and pre-heating bath are eliminated. Deterioration of manifold tubing is minimized, while maintaining optimal machine sensitivity by adding borate and water to the reagent. Serum glucose was measured by the automated o-toluidine and Cu—neocuproine methods with similar, highly correlated results. Thus, the "normal limits" are unchanged and the same recorder graph paper may be used. A direct manual micro-method is also described, in which an anhydrous o-toluidine reagent is used. Results of manual and automated methods agree satisfactorily.