Abstract: An automated patient sample analysis instrument uses assay cartridges which are pre-loaded with all reactants needed to perform an assay. Photometric measurements are performed on the cartridges while spinning at variable speeds in a centrifuge. Both axial and transverse measurements can be made on the cartridges. Multiple optical channels can be read by single detector. The instrument is well suited for low volume and for use by unskilled individuals. The photometric measurements are made by dividing the width of a measurement window into n intervals, measuring an optical result in one of the n intervals in each of n rotations of the cartridge, repeating the measurement process x times, summing or averaging the x results for each of the n intervals and selecting y of the largest resultant averaged or summed measurements as representative of the maximum measurement for the window.

Abstract: A self-balancing apparatus for a centrifuge is disclosed which employs two arcuately movable counterweights. The centrifuge has a plurality of receptacles for receiving one or more assay cartridges. Control apparatus in the centrifuge determines the location and number of received cartridges. Desired counterweight positions are then calculated which will substantially balance the centrifuge. The counterweights are moved into these positions prior to the centrifuge being operated at high speeds.

Abstract: Methods and devices for separating bound label from unbound label within an assay mixture and for predispensing assay reactants in self-contained assay vessels, as well as a method for detecting the presence and/or amount of an analyte within a fluid sample, and a reusable detection vessel for use therein and with specific binding assays in general are disclosed. Significant to the separation of bound label from unbound label is the use of a cushion comprising generally one primary layer and in some cases one or more secondary layers.

Abstract: Methods and devices for separating bound label from unbound label within an assay mixture and for predispensing assay reactants in self-contained assay vessels, as well as a method for detecting the presence and/or amount of an analyte within a fluid sample, and a reusable detection vessel for use therein and with specific binding assays in general are disclosed. Significant to the separation of bound label from unbound label is the use of a cushion comprising generally one primary layer and in some cases one or more secondary layers.