A semi-automated method for the determination of multiple membrane ATPase activities.

A simple semi-automated method for the determination of erythrocyte plasma membrane (Mg2+)-ATPase, (Na+ + K+ + Mg2+)-ATPase, and the (Ca2+ + Mg2+)-ATPase is described in detail. A nonautomated ATPase enzyme assay for multiple membrane ATPases and automated methods for determination of inorganic phosphate as well as membrane-bound protein are described. Together, the methods represent a system that has the flexibility and sensitivity for basic research applications and the capacity to process relatively large numbers of samples as is common in clinical laboratory screening.