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We describe a multichannel heterogeneous immunoassay analyzer in which a sample is split between disposable reaction trays in a group of linear tracks. The system's pipettor uses noninvasive sensing of the sample volume and disposable pipet tips. Each assay track has (a) a conveyor belt for moving reaction trays to predetermined functional stations, (b) temperature-controlled tunnels, (c) noncontact transfer of the reaction mixture between incubation and detection wells, and (d) single-photon counting to detect a chemiluminescence (CL) signal from the captured immunochemical product. A novel disposable reaction tray, with separate reaction and detection wells and self-contained fluid removal, is used in conjunction with the transfer device on the track to produce a carryover-free system. The linear immunoassay track has nine predetermined positions for performing individual assay steps. Assay step sequence and timing is selected by changing the location of the assay modules between these predetermined positions. The assay methodology, a combination of microparticle capture and direct detection of a CL signal on a porous matrix, offers excellent sensitivity, specificity, and ease of automation. Immunoassay configurations have been tested for hepatitis B surface antigen and for antibodies to hepatitis B core antigen, hepatitis C virus, human immunodeficiency virus I and II, and human T-cell leukemia virus I and II.

We describe a reaction tray for a heterogeneous chemiluminescence (CL) immunoassay having the following features: separate sample incubation and signal detection wells; a design that allows for noncontact transfer of the reaction mixture from incubation wells to detection wells; surface features to mate with a detector and create a light-tight seal for CL detection; and self-contained means for liquid removal. The reaction mixture is transferred by injecting a wash solution from a group of nozzles into the incubation well. Quantitative transfer of microparticles (transfer efficiencies greater than 95% and CV less than 5%) is achieved by injecting two 300-microL pulses of transfer solution at a rate of 2.1 m/s. The performance of the tray and method of transfer is tested by determining the precision of CL signal for a sample containing a concentration of anti-hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg) close to the cutoff value for the assay.

We describe an apparatus for measuring signals emanated from two heterogeneous chemiluminescence immunoassay (CLIA) configurations: antibody-coated polystyrene beads, in reaction tray wells, and microparticles captured by a porous matrix. An optics and fluidics design which allows the use of a common detection head for these two different assay configurations is described. The detection head moves along three Cartesian coordinates to create a localized light-tight compartment around each individual disposable reaction vessel. Reproducibility of the light seal, trigger solution delivery, and mixing is achieved for acridinium-labeled CLIA. The coated polystyrene beads configuration is tested using beta HCG, CEA, and TSH assays. The microparticle-capture configuration is tested using beta HCG and HBsAg assays. The microparticle capture CLIA has shorter incubation times and the potential for ease of automation.

In a randomized study 30 patients (age 59 +/- 7) with angiographically confirmed coronary artery disease were treated with either gallopamil (15 patients) or diltiazem (15 patients). After a 48-h-run-in period of treatment with nitrates the gallopamil group was treated with 3 X 60 mg/day, and the diltiazem group was treated with 3 X 50 mg diltiazem/day. As criteria for the efficacy of therapy the anginal frequency, the nitroglycerin consumption, and exercise tolerance were monitored. During exercise the blood pressure in the 50-watt-level, the product of blood pressure, and pulse rate at 50 watts and at the maximal workload level, the ischemic index was calculated as the product of blood pressure, pulse rate, and ST-segment depression/Watt. Later the exercise tolerance and the difference of the exercise tolerance before and after the drug period was measured. The following parameters improved under gallopamil therapy: the gallopamil group showed a significant reduction of the anginal frequency/week (10 +/- 8 down to 3 +/- 2, p less than 0.001), the nitroglycerin consumption (1.4 +/- 1.4 down to 0.3 +/- 0.6, p less than 0.001), the ischemic index (from 63 +/- 24 down to 46 +/- 17, p less than 0.01), and the exercise tolerance (740 +/- 610 up to 1140 +/- 670, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)