Abstract
We define the following criteria for enzyme assays as being beyond compromise: narrow bandpass double-beam spectrophotometer, multiple readings on the sample (kinetic procedure), temperature control of assay reaction mixture to ±0.1°C, wash-out between samples less than 1% of the preceding sample, and sample size of 100 µl or less. In addition, the following specifications for a system were considered desirable: automatic handling of the sample from initial pipetting through readout, adequate computer compatibility, versatility so that new procedures and different methods could be used, relatively short set-up time, and hard-copy backup in the event the computer failed. We have developed a system for enzyme assays that meets all of the above criteria. It consists of an analyzer (Beckman DSA-560) coupled to two modified Eskalab Spectrophotometers Alpha. The system is controlled via a special-purpose hybrid computer designed and built in our laboratory. Data from the system is analyzed on-line by an IBM 1800 computer. Details of the operation and reliability of the system in a routine clinical chemistry laboratory are discussed.