A fully automated system for performing fluorescence polarization immunoassay has been developed. Reagents for each assay are contained in coded reagent packs, and no reagent reconstitution is required. A common buffer is used for all assays, minimizing changeover and set-up times for each assay. A single sample may be assayed in 5 min, or 20 samples in 10 min. A single-tube blank subtraction for each sample results in highly precise polarization values and obviates sample interferences. We have used this method for assays of gentamicin, theophylline, phenytoin, and phenobarbital. CVs are 1-4%, and the results correlate well with those by other methods. Because of the instrument design and the stability of the reagents, daily calibration is not required; samples may therefore be run immediately upon receipt or batched as desired.

An immunoassay system based on enzyme immunoassay technology has been developed for quantitative panel testing. The system includes test card disposables, reagents, and an instrument. Patients' samples are processed semiautomatically in the instrument with minimum user intervention. The test card has multiple test areas at individual locations on a membrane solid phase so that simultaneous determinations from a single specimen are possible. Each panel also includes positive and negative reagent procedural controls. Factory-determined calibration curves for each analyte are provided in barcode form with each test kit. The reagents include a specimen dilution buffer, enzyme conjugate, and precipitogenic substrate. Up to 10 test cards at a time can be processed in random-access and continuous-access modes, with automated agitation of sample and reagents over the solid phase, temperature-controlled incubation, and membrane washing and reading, data reduction, and printout of results. The optical reader measures diffuse reflectance and features source intensity and wavelength compensation.

This instrument, developed for quantitating fluorescence polarization immunoassays, automatically measures both polarization components and computes a polarization value corrected for background and optical bias. An electronically switched liquid crystal provides a nonmechanical means of rotating the plane of polarization in the excitation optics. The electronic design features digital integration and microprocessor controlled functions. Readings are made in disposable 12 X 75 mm round culture tubes. in less than 10 s. Results are precise to 0.001 polarization unit, linear from 10(-7) to 10(-10) mol of fluorescein per liter, and correlate well with those obtained with other "high-performance" instrumentation.

We have developed a new system for clinical chemistry analysis, the Vision System, in which centrifugal force is used to separate whole blood, measure reagent and plasma volumes, and complete all steps required for a spectrophotometric analysis. The system is based on use of a multichambered plastic test pack containing liquid reagents, which can be centrifuged at 500 X g in two planes, oriented at right angles to each other. Alternating centrifugal fields allows liquid reagents and plasma to flow into highly precise measuring and mixing chambers. A unique flash lamp and diode array spectrometer provide for optical measurements of 10 test packs at as many as eight wavelengths simultaneously. The temperature of each individual test pack is controlled by using a flash lamp coupled to a liquid crystal temperature sensor. Microprocessor control allows as many as 10 different chemistry reactions to be measured simultaneously on whole-blood, plasma, or serum samples. Comparison with results by an established batch-photometric analyzer demonstrated excellent precision and accuracy for various clinical chemistry tests.

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