Beckman Instruments, Inc.

Beckman Coulter, Inc.

Charles L Dodson

Yagang Liu

Tsong-Tseh Tsay

Robert J Obremski

Tung Rung Wang

John Warwick Silzel

Bibijana Cercek

Zhou Shaomin

A microscale binding assay, analyte binding array, and kits are disclosed, which exploit the mass action law to harvest analyte from a liquid sample. This is achieved by fabrication of sorbent zones having up to ten times the binding capacity per unit area generally obtained on polystyrene microtiter plates. The resulting arrays substantially deplete the liquid solution of analyte during incubation. Accordingly, the assays respond to total mass of analyte in the sample, not analyte concentration. This approach, coupled with direct fluorescence detection in the NIR, yields maximal signal intensity and low background for optimal sensitivity.

Detection of very low quantities of analyte bound to a solid phase

Methods and apparatus are provided for identifying a radionuclide in a liquid sample containing at least one unknown radionuclide, in which specific properties which are essentially linear over extended quench ranges are employed as the primary basis for identifying the radionuclide. For example, the endpoint or maximum energy of a sample is related to Mantel's average energy or a property proportional to the average energy (such as isotope center number) in order to establish characteristic relationships for radionuclides of interest; comparison of measured values with characteristic values for specific radionuclides may in some cases be sufficient to identify a radionuclide unambiguously. The relationships between isotope center number, full width of the spectrum at half its maximum height and maximum energy may be exploited to provide a pair of characteristic equations for each radionuclide. In those instances where some ambiguity might arise, other features of the spectrum (such as maximum peak height or number of peaks present) are employed to distinguish between nuclides which are not clearly identified by the first step.

Method and apparatus for identifying a radionuclide in a liquid

Disclosed herein is a liquid scintillation solution useful for alpha particle emission and beta particle emission discrimination. Most preferably, the liquid scintillation solution comprises at least one naphthalene derivative enhancing agent; at least one solvent; and at least one fluor. In a particularly preferred embodiment, the liquid scintillation solution comprises di-isopropyl naphthalene as the enhancing agent; phenylxylethane as the solvent; and 2-(4'-biphenyl)-6-phenylbenzoxazote as the fluor.

Liquid scintillation solution useful for alpha particle emission and

Determining whether a liquid scintillation sample is single- or multi-phase includes transforming all or a portion of a Compton Spectrum of data into different namely integrated, geometric space. A predetermined parameter in the selected geometric space, indicative of the phase content of the sample is selected, and compared with the data in the different geometric space. This provides a determination of the phase content of the sample. The linearity of the data indicates the phase content.

Detecting multiple phases in liquid scintillation samples

Monitoring and measuring colored samples by the techniques of liquid scintillation counting employs the relationship of absorbance and counting efficiency. A determination of whether color quench correction is required is made. Should a color monitor detect a color intensity which requires color correction, then efficiency correction is performed here. Both the color monitor and the color correction of efficiency are incorporated into a liquid scintillation counter which performs color monitoring, measurement and correction automatically.

Color monitoring in liquid scintillation systems

An efficiency extrapolation method is used in liquid scintillation counting for determining activity in an unknown sample. A dynamic and automatic determination of the range of the pulse height spectrum is used to permit a counting measurement in highly quenched samples, and with isotopes having low energy end points. A selected linear regression equation is extrapolated to provide the determination within a predetermined error established by a least squares condition.

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Orange, CA, United States of America

Charles L Dodson