A rapid, flexible method for biochemical assays using a microtiter plate reader and a microcomputer. Application for assays of protein, Na,K-ATPase and K-p-nitrophenylphosphatase.

A computerized system which greatly accelerates and eases the collection, storage, and analysis of data has been applied to several standard biochemical assays. The system uses a commercially available microtiter plate reader connected to an Apple IIe microcomputer via a standard serial port. Data are transmitted automatically from the reader to the microcomputer, where they can be viewed, printed, further analyzed immediately, or stored on a diskette for later retrieval and processing. Some or all of the data may be entered manually. The program calculates a linear least squares best fit to a standard curve after correcting all data for blanks, then determines the quantities of substrate or product contained in each well of a microtiter plate. Data from two plates may be combined, enabling calculation of enzyme specific activities. This system can be adapted to any assay whose final step can be performed by a microtiter plate reader. Its use is described for determination of protein concentration, Na,K-ATPase activity, and K-stimulated p-nitrophenylphosphatase activity.