Abstract: An apparatus for improving the procedure for quantifying the volume of liquid dispensed by a liquid-dispensing mechanism of an analytical instrument. The apparatus of this invention comprises (a) at least one weigh cup; (b) at least one standard mass; (c) at least one transducer assembly to convert a value of weight to an electrical response; and (d) at least one electronic circuit for converting the electrical response to a measurement of volume. This invention provides a method for calibrating readings of the volume of liquid dispensed by a liquid-dispensing mechanism of an analytical instruments so that absolute measurements of the volume of liquid dispensed can be obtained.

Abstract: Embodiments described herein provide methods and apparatuses for thermally controlling an instrument. According to one embodiment, an apparatus includes a heater and a source of electrical energy electrically connected with the heater for energizing the heater to produce thermal energy. A driver is electrically connected with the heater and the source of electrical energy for controlling application of electrical energy to the heater. A sensor is electrically connected with the heater for detecting thermal energy produced by the heater responsive to the electrical energy from the source of electrical energy. A controller is electrically connected with the driver and the sensor for controlling production of thermal energy by the heater responsive to electrical energy from the source of electrical energy. Another embodiment provides a method in which a heater is electrically connected with a relatively reduced thermal energy reference resistor.

Abstract: Embodiments of the invention provide methods of preparing an activated acridinium microparticle. Generally, the methods involve direct covalent coupling or an affinity format. The direct covalent coupling method involves coating a microparticle with a proteinaceous compound. Then, a 10-methyl-N-tosyl-N-(2-carboxyethyl)-9-acridinium carboximide trifluoromethane sulfonate is coupled to the proteinaceous compound. In the affinity format, a microparticle is coated with a biotinylated proteinaceous compound. The microparticle is reacted with an anti-biotin labelled 10-methyl-N-tosyl-N-(2-carboxyethyl)-9-acridinium carboximide trifluoromethane sulfonate. Methods are also provided for using such a microparticle. Those methods of use can estimate transfer efficiency, calibrate optics, and measure membrane pore size of a chemiluminescence based instrument. Test elements for analytical instruments are also provided.