Reader for conducting assays

Abstract

An analytical device that can be used to conveniently and accurately assay plural vessels. In one exemplary embodiment, a pair of LED sources provides illumination through a pair of radial waveguides to plural vessels arranged in a pair of substantially concentric and circular rows about the LED sources. A light pipe receives light transmitted through a vessel from each radial waveguide and reflects the received light downward to a single printed circuit board that contains a photodiode for each light pipe, as well as processing circuitry. The first LED source / radial waveguide optical is used to confirm the presence of a vessel, and the second is used to perform, e.g., turbidometric and / or colorimetric assays upon an analyte within the vessel. The vessel is incubated in a vessel support that includes a heat conducting base and a heat insulating cover. Heat is supplied by a DC heater.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. provisional application No. 60 / 167,618 filed Nov. 26, 1999.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention is directed towards the Pyros Kinetix reader for conducting assays. More specifically, this invention is directed to providing an analytical device that, in one embodiment, conveniently and accurately assays both turbidity and chromogenic reactions in plural vessels. [0004] 2. Discussion of the Background [0005] Optical techniques are commonly used to transduce a number of different chemical and biological parameters. Among many thousand such examples, turbidometric measurements can be used to bioassay and / or bioscreen for the presence of endotoxin using Limulus amebocyte lysate (LAL) such as PYROTELL-T (Associates of Cape Cod, Falmouth, Mass.). Similarly, chromogenic measurements can be used to bioassay and / or bioscreen for the presence of endotoxin usi...

AI Technical Summary

Benefits of technology

"The invention provides a novel method and device for conducting assays simultaneously in multiple vessels. The device includes a PYROS KINETIX READER and a single LED source providing illumination to plural vessels through a radial waveguide. The LED source can be modulated using a microprocessor or mechanically. The device can include plural groups of vessels at different radii about a center point or a single printed circuit board with plural phototransducers. The method involves generating light using a LED, radially guiding a portion of the light, transmitting a portion of the guided light through a plurality of vessels, and transducing a portion of the transmitted light to assay a sample. The generated light can be transmitted through a side or bottom portion of the vessels and used to detect their presence. The method can also involve modulating the LED source to yield a background measurement. The invention reduces device component and assembly costs, minimizes the size of the device, makes repair easier, and allows a user to incubate plural assays in plural vessels using a minimum of power while maintaining a desired incubation temperature."

Problems solved by technology

Incandescent light sources are however only suitable for performing certain types of assays since their emission intensity is primarily in the IR and long wavelength portion of the visible spectrum.

Moreover, incandescent light sources require intensity adjustments to maintain a relatively constant emission flux, have limited operational lifetimes, and, as a consequence of resistive heating of the filament, dissipate large amounts of heat that often complicate temperature control in incubators.

Finally, since incandescent sources require relatively large amounts of power, they are commonly driven by high power AC sources such as line sources and microcontroller-based modulation of incandescent source intensity is relatively difficult to implement.

As both the light transduction and light generation described by Noeller (U.S. Pat. No. 4,784,947) only occurs at discrete times, continuous monitoring and automated data analysis is not possible.

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