4812220 Enzyme sensor for determining a concentration of glutamate

PATENT ABSTRACTS

286

4811218 REAL TIME SCANNING ELECTROPHORESIS APPARATUS FOR DNA SEQUENCING Michael Hunkapiller, Charles Connell, William Mordan, John Lytle, John Bridgham assigned to Applied Biosystems Inc A real-time, automated, nucleic acid sequencing apparatus that offers high speed, definitive sequencing on many samples at the same time. The apparatus permits more than one clone to be sequenced at a time, thus vastly decreasing the time required to sequence longer fragments and reducing sequencing costs accordingly. The apparatus detects electromagnetic radiation from a plurality of lanes in an electrophoresis system wherein the plurality of lanes are arranged in a planar array. The apparatus includes an optical system for detecting the radiation at a plurality of wavelengths and is made up of a collection element, a filter for selectively transmitting the plurality of wavelengths received from the collection element, and a detection sysJ~em for measuring intensity of the radiation received from the filter means. A translational stage is used for mounting the optical system and for moving the optical system parallel to the planar array in order to move the collection element back and forth across the lanes in order to receive radiation from the lanes, one lane at a time during electrophoresis. Also included is a computer system for controlling the filter and the stage, and for receiving intensity data from the detector and correlating that data with the corresponding lane and corresponding wavelengths transmitted by the filter in substantially real time.

4812220 ENZYME SENSOR FOR DETERMINING A CONCENTRATION OF GLUTAMATE Takeaki Iida, Takeshi Kawabe, Niiza, Japan assigned to Unitika Ltd Disclosed is an enzyme sensor for determining a concentration of glutamate comprising an immobilize enzyme acting specifically to a substrate and a transducer for converting the quantitative change of a substance or heat which is produced or consumed during an enzyme reaction to an electrical signal, wherein the enzyme is glutamine synthetase and the transducer is the

pH glass electrode or ion-sensitive field-effect transistor (ISFET). The enzyme sensor can be miniaturized and can accurately determine a concentration of glutamate even when it is low.

4812394 FLOW CYTOMERIC MEASUREMENT OF DNA AND INCORPORATED NUCLEOSIDE ANALOGS Frank A Dolbeare, Joe W Gray assigned to University of California A method is provided for simultaneously measuring total cellular DNA and incorporated nucleoside analog. The method entails altering the cellular DNA of cells grown in the presence of a nucleoside analog so that single stranded and double stranded portions are present. Separate stains are used against the two portions. An immunochemical stain is used against the single stranded portion to provide a measure of incorporated nucleoside analog, and a double strand DNA-specific stain is used against the double stranded portion to simultaneously provide a measure of total cellular DNA. The method permits rapid flow cytometric analysis of cell populations, rapid identification of cycling and noncycling subpopulations, and determination of the efficacy of S phase cytotoxic anticancer agents.

4812395 METHOD FOR DETECTING ENZYMATIC ACTIVITY USING PARTICLE AGGLUTINATION Robert A Ballas, William A Frey assigned to E I Du Pont De Nemours and Company A method is disclosed for determining enzymatic activity in a liquid sample by particle agglutination or inhibition of particle agglutination.

4812399 ANALYTICAL ELEMENT AND METHOD FOR THE DETERMINATION OF CREATININE OR CREATINE John C Mauck, Linda A Mauck, Gary E Norton assigned to Eastman Kodak Company