Abstract: A multi-functional photometer includes a scanning mechanism having a housing that bears a movable linkage. The linkage is coupled to an optical scanning head and incorporates light-transmitting paths with at least one reflective surface for transmitting radiant energy to and from the scanning head. The arm comprises a C-shaped elbow member, pivotally attached to a shoulder member. In turn, the shoulder member of the arm is pivotally connected to the housing. In one embodiment the reflective surfaces are optically coupled and are mounted onto the housing, shoulder member and elbow member, such that the shapes of the light-transmitting paths remain fixed regardless of the orientation of the arm. The housing further incorporates a Cartesian-coordinate table for positioning the scanning head with respect to a microplate that contains a plurality of analyte samples.

Abstract: A capillary electrophoresis separation matrix for single-stranded nucleic acids, along with methods for using and preparing the matrix, are disclosed. The separation matrix provides denaturing conditions and contains hydroxyethyl cellulose (HEC) in combination with urea, and preferably also includes formamide. The separation matrix may be used for DNA sizing and sequencing applications and provides a single-base resolution to approximately 500 base pairs. The separation matrix is inexpensive, easy to prepare, requires no polymerization steps, and is of low enough viscosity to be pumped easily into and out of capillary tubes for electrophoresis. The low viscosity allows for high throughput of samples and reuse of the capillary tubes for numerous separations.

Abstract: A method and apparatus for causing a computer to drive one or more external devices is provided. A computer executes instructions which cause the computer to display an experiment design region and a set of icons. A user copies the icons into the experiment design region to specify the various phases of an experiment. By setting controls in windows associated with the icons, a user specifies how the general stages of an experiment will be performed. Specifically, a user operates controls associated with the icons in the experiment design region to specify which devices will be used in the experiment, how data generated during the experiment will be stored, how different sets of data are related, calculations to be performed on the data, and the format of reports generated based on the data gathered during the experiment. The user specifies the operations to be performed by constructing an icon sequence in a scheduler window.

Abstract: A self-aligning mechanism for positioning analyte receptacles comprises a loading carriage which bears a tray. In one embodiment, the carriage is slidingly mounted in a structure and includes three guide pins and a stop pin. In this embodiment, the tray has a leaf spring attached at the rear thereof, a lateral protuberance for contacting the structure, and two frontal and one lateral oblique slots. A pair of vertical contact planes, orthogonally disposed with respect to each other, are formed on the top surface of the tray.

Abstract: An LED point imaging scanner for stimulating and for reading fluorescent and reflective signal radiation from a target sample is disclosed. The LED light source is mounted on a scan head and is focused into the pinhole aperture of a spatial filter, then collimated and focused to a spot on the sample. The spatial filter in the illumination path, or an optical fiber serving the equivalent function, effectively restricts the incoherent LED light and creates a point light source. Signal radiation from the sample is collected through the scan head and the returning light beam is collimated and focused onto the receiving section of a detection means. A spatial filter in the path of the returning beam may also be utilized. The detection means is either a small detector which is mounted directly on the scan head or an end of an optical fiber which transmits the point image to a remotely-positioned stationary detector.

Abstract: A multi-functional photometer includes a scanning mechanism having a housing (10) that bears a movable linkage (12). The linkage is coupled to an optical scanning head (18) and incorporates optical fibers for transmitting radiant energy to and from the scanning head. The arm comprises a C-shaped "elbow" member (14), pivotally attached to a "shoulder" member (16). In turn, the "shoulder" member of the arm is pivotally connected to the housing. Dynamic couplings join the optical fibers such that the shapes thereof remain fixed regardless of the orientation of the arm. The housing further incorporates a Cartesian-coordinate table (20) for positioning the scanning head with respect to a microplate (22) that contains a plurality of analyte samples.

Abstract: A capillary electrophoresis separation matrix for single-stranded nucleic acids, along with methods for using and preparing the matrix, are disclosed. The separation matrix provides denaturing conditions and contains hydroxyethyl cellulose (HEC) in combination with urea, and preferably also includes formamide. The separation matrix may be used for DNA sizing and sequencing applications and provides a single-base resolution to approximately 500 base pairs. The separation matrix is inexpensive, easy to prepare, requires no polymerization steps, and is of low enough viscosity to be pumped easily into and out of capillary tubes for electrophoresis. The low viscosity allows for high throughput of samples and reuse of the capillary tubes for numerous separations.

Abstract: A fluorescence detection scanner and method employing a fiberoptic collector, positioned adjacent to the scanning plane of the excitation beam, with a light collecting surface which is oriented to reject back-scattered excitation light from the incident surface of the sample support. The scanning plane of the excitation beam is off normal relative to the incident surface of the sample support and the light collecting surface is located within the area defined by the resulting acute angle of incidence. The light collecting surface is angled away from the location at which the incident excitation beam intersects the surface of the sample support so that back-scattered excitation light does not enter the optical fibers. The orientation of the light collector results in a four to five-fold decrease in excitation-light background without attenuation of the fluorescence emitted by the sample.

Abstract: Using storage phosphor recording media, two exposures are made of a sample containing two target substances tagged with different radiative emitters, for example 32-P and 35-S. The first exposure, image 1, is of the sample directly on the phosphor screen. The second exposure, image 2, is made with the appropriate absorption material between the sample and screen. Both images are captured. By using simultaneous equations isotope contributions of each label can be determined. Quantitative assessment of the contributions of the isotopes, and hence the target substances, are made by calculating isotope efficiencies both with and without the absorption filter.

Abstract: A method and system for imaging unstained smaple material constituents on a gel electrophoresis unit. The system includes a gel electrophoresis unit, preferably having a pH gradient gel thereon, phase detection optics including a collimated light source, shearing interferometer, phase contrast microscope or schlieren microscope, an image digitizer, and data processing electronics, such as a computer, for determining the concentration of sample constituents at each position on the electrophoresis unit. The method relies on the difference in index of refraction between sample material and gel material to introduce optical path differences in light rays passing through the material. The modified light is subjected to shearing interferometry to locate gel-sample boundaries, phase imaging to directly image the sample, or a laser scanner for directly measuring the deviation in a light beam due to the sample.