E.i. Dupont De Nemours and Company

Nanodrop Technologies, LLC

Other

Charles W Robertson, Jr

Donald H Brunk

James M Prober

Rudy J Dam

Charles F Collier

George L Trainor

Frank W Hobbs

Damian W Ashmead

David J Regester

Thomas A Tokash

Jonathan Pundt

Robert K Kobos

Scot D Abbott

David T Bach

Anders J Wellings

Joel Bruce Hansen

Paul S Zdinak

Lynne E Anderson

Shay E Polsky

Dale Heintzelman

Catherine T Williams

An apparatus is described in which an optical fiber is mounted within a fiber optic holder which includes the non-rotating shaft of a linear actuator. The fiber holder may be held captive in order to restrain the fiber holder and, consequently, the fiber mounted therein, from rotating during operation of the linear actuator, thereby resulting in linear travel with minimal rotational effects and minimal change in optical alignment of the fiber during travel. In addition, an optical path length sensor in conjunction with an optimized absorbance method of operation is utilized herein to provide micron precision of the displacement between respective receiving and transmission fibers so as to enable precise absorbance measurements from about 0.005 up to about 2.0 Absorbance Units for any given path length.

Optical path length sensor and method for optimal absorbance measurements

A dual-mode method and apparatus of selectively measuring samples in either a vessel or as a surface tension retained sample held between two opposing pedestals is introduced. In either configuration, such modes further contain optical paths from a source system through a small-volume or large-volume sample to a spectrometer based system. Such a system enables a user to measure samples with absorbances ranging from about 0.005 up to about 2.0 Absorbance Units for any given wavelength.

Dual sample mode spectrophotometer

A photometer is provided with modular lighting units wherein each lighting unit includes one or more light emitters. A user may select a desired lighting unit and install it within a photometer base unit, and thereafter activate one or more of the emitters (which may emit light of different wavelengths) to illuminate a specimen. The light provided by the specimen in response can then be captured at a detector, and analyzed to provide an indication of the specimen's characteristics. Different lighting units may optionally include one or more input light adapters (filters or polarizers which modify the light provided by the emitter(s) to the specimen), and/or one or more output light adapters (filters or polarizers which modify the light provided by the specimen to the detector). Users may therefore select lighting units with emitters and light adapters which are particularly suited for detection/analysis of particular specimens and/or components therein.

Photometer with modular light emitter

A gel cassette useful in electrophoretic separation of molecular fragments is disclosed, in which a gelatinous substrate is uniquely configured to concentrate similar separated fragments. Containment means is also disclosed which provides for the desired configuration of the substrate. The containment means further includes a cover design which locks into an open position to eliminate cross contamination. In addition, processes for the preparation of such cassettes and for use of the cassettes in separation and transfer apparatus are disclosed.

Gel cassette for enhanced electrophoretic separation and processes for

There is disclosed an electric mower, preferably of the riding type, in which microcontrollers are interposed between quadrature controllers and motors operating each of the drive wheels. The microcontrollers are programmed to provide pulse width modulated current drive control and braking. Other functions are controlled electronically to assure operations that are not harmful to the operator, the motors, the battery or the lawn being mowed.

Electric lawn mower with intelligent control

A bowed framed membrane is disclosed for use in automated direct blot electrophoresis and subsequent membrane process steps to develop a chemiluminescent image of the resultant blot of selected fragments and to detect that image. A frame made from a thin rigid plastic plate such as polyethylene is provided with a window. A membrane covers that window and is bonded on two opposing sides only while the frame is held in a bowed condition. The membrane is maintained under tension during processing by the bowing permitting processing at the elevated temperatures used in molecular biological procedures without loss of flatness. Processes for preparing such frames and various utilities are also disclosed.

Bowed framed membrane, processes for the preparation thereof, and uses

Reagent carrier

A disclosure is made of automatic apparatus for processing transfer membranes to which a blot pattern of molecular fragments has been bound so that the pattern may be optically visualized. The apparatus is characterized by at least one open processing cell and two systems for pumping; one selectively controlled to direct fluid to and from functional units and one which is closely coupled to the cell and recirculates the fluid in the cell to assure adequate and thorough treatment therein by uniform fluid flow across both sides of the membrane.

Apparatus for fluid treatment of framed membranes

A DNA sequencing system and method are described to detect the presence of radiant energy emitted from different excited reporter dye-labeled species (DNA fragments) following separation in time and/or space, and the identity of the species which emit radiant energy closely spaced in wavelength. Functions of the emitted energy are obtained which vary over the wavelengths of the closely spaced spectra in different senses and the functions ratioed, whereby the ratio is indicative of the identity of the DNA fragments. The emitting portion of the reporter-labeled DNA fragment is preferably one of a family of fluorescent dyes based on 9-carboxyethyl-6-hydroxy-3-oxo-3H-xanthene. These xanthene dyes are covalently attached to the DNA fragments through the carboxylic acid functionality, preferably via an amide linkage. The dyes may be protected by including an alkoxy group at the 9-position. A spacer may be inserted between the dye and the amine. The fluorescent dye preferably is attached to the DNA chain terminators and provides many advantages. Thus only DNA sequencing fragments resulting from bona fide termination events will carry a reporter. The DNA sequencing may also be labeled using the xanthene dyes which have general utility as fluorescent labels. Also acyclonucleoside triphosphates are described as being useful as chain terminators in DNA sequencing using a modification of the Sanger method.

Method, system and reagents for DNA sequencing

Improved apparatus for the handling and detecting of an electrophoretic transfer membrane is disclosed herein, the improvement comprising guide apparatus designed to accommodate the transfer membrane, a pressure head positioned relative to the guide apparatus to releasably engage the membrane, and light shielding apparatus positioned relative to the guide apparatus to selectively enclose about the transfer membrane. The apparatus is operated so that the pressure head engages a flexible portion of the transfer membrane containing an electrophoretic blot while it is in a position appropriate for detection. There is also disclosed herein a process for utilizing the apparatus of the invention. In the process drying and optionally heating of the membrane where the blot has been contacted with enzyme-triggered 1,2-dioxetanes, to enhance the resulting chemiluminescent signal, is disclosed.

Apparatus for the handling of electrophoretic transfer membranes and for

Method systems and reagents for DNA sequencing

A DNA sequencing system and method are described to detect the presence of radiant energy emitted from different excited reporter dye-labeled species (DNA fragments) following separation in time and/or space, and the identity of the species which emit radiant energy closely spaced in wavelength. Functions of the emitted energy are obtained which vary over the wavelengths of the closely spaced spectra in different senses and the functions ratioed, whereby the ratio is indicative of the identity of the DNA fragments. The emitting portion of the reporter-labeled DNA fragment is preferably one of a family of fluorescent dyes based on 9-carboxyethyl-6-hydroxy-3-oxo-3 H-xanthene. These xanthene dyes are covalently attached to the DNA fragments through the carboxylic acid functionality, preferably via an amide linkage. The dyes may be protected by including an alkoxy group at the 9-position. A spacer may be inserted between the dye and the amine. The fluorescent dye preferably is attached to the DNA chain terminators and provides many advantages. Thus only DNA sequencing fragments resulting from bona fide termination events will carry a reporter. The DNA sequencing may also be labeled using the xanthene dyes which have general utility as fluorescent labels. Also acyclonucleoside triphosphates are described as being useful as chain terminators in DNA sequencing using a modification of the Sanger method.

A separation and direct blot transfer module useful in gel electrophoresis is disclosed in which a transfer membrane stabilized by a frame is moved substantially orthogonally relative to the plane of the separation gel while in minimal contact with the end of the gel toward which molecular fragments are driven electrophoretically. The frame moves at a controlled velocity in a selected direction away from a line of contact that generates a controlled tension in the membrane which is a function of the loading on the line of contact. The module is particularly amenable to automated processing. Apparatus for automated separation, transfer, membrane processing, detection and identification is disclosed in which the module of the invention is employed.

Apparatus for direct blotting and automated electrophoresis, transfer

An optical inspection apparatus using a polychromatic source to generate a channeled spectrum for measuring the variations in the thickness of a thin transparent web as the web moves on-line with respect to an optical inspection station.

Growing community of inventors

Rockland, DE, United States of America

Charles W Robertson, Jr