Abstract:
Fluorescence imaging system includes objective (21) which is achromatic and has an external entrance pupil (29), serves as a condenser for the system, and positioned above sample (23) in close proximity to one another. Laser (18) directs collimated light (19) to scan device (20) located at entrance pupil (29). Scan device (20) reflects, refracts, or diffracts light through objective (21) to illuminate a spot (22) on the sample's surface, and illuminates a line or an area on the sample surface by varying the angle of laser light into objective (21). Sample (23) emits fluorescent light (24) in response to the illumination. The fluorescent light (24) is collected by objective (21) and passes through the system along the path of the illumination light. Wavelength-discriminating dichroic filter (25), placed along the optical axis between laser (18) and objective (21), directs fluorescent light (24) onto photodetector (26) to produce a signal representing the sample surface emitting the fluorescent light. Display (37) displays the digitized data in a raster format.
Abstract:
The present invention features two flat-field, telecentric, infinite conjugate, achromatic objectives (32 and 34) each of which has an external pupil lying in a common plane located equidistant from the two objectives, defining a mechanically accessible central pupil (30) of an imaging system centered in the common plane (28). Each of the objectives is afocal in the common plane, with one of the lenses forming a focal plane proximate to a sample. The lenses are adapted to provide varying levels of magnification while keeping constant the number of resolvable points in the field of view. An array detector (14) is positioned proximate to a focal plane formed of the remaining objective lens (34). The double objective lens assembly is described as being included in transillumination and epi-illumination systems.
Abstract:
A self-aligning mechanism for positioning analyte receptacles (108) comprises a loading carriage (200) which bears a tray (244). In one embodiment, the carriage (200) is slidingly mounted in a structure (202) and includes three guide pins (222, 224, 226) and a stop pin (238). In this embodiment, the tray (244) has a leaf spring (280) attached at the rear thereof, a lateral protuberance for contacting the structure (202), and two frontal and one lateral oblique slots (252, 254, 258). A pair of vertical contact planes (272, 274), orthogonally disposed with respect to each other, are formed on the top surface of the tray (244).
Abstract:
A microspot deposition system (12) featuring a hollow cylindrical wall (26) extending from a closed end (28), terminating in an open end (30) and including a longitudinal gap (34) extending from the open end (30) toward the closed end (28) to allow the rapid exhaustion of the atmosphere and efficient cleaning within the cylindrical wall (26). The cylindrical wall (26) defines a lumen (32) with both the lumen (32) and the gap (34) adapted to facilitate capillary action of liquid in fluid communication therewith to form a meniscus (46) proximate to the open end (30). To facilitate deposition of liquid contained within the lumen (32), the gap (34) may be tapered so that it is narrowest proximate to the open end (30). The narrowed portion of the gap (34) results in a meniscus (46) having a reduced area to ensure preferential fluid flow toward the open end (30), which facilitates deposition via capillary action between the liquid in the lumen (32) and a working surface (52).
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. In the figure, line (10) represents peak spacing and line (20) representa peak width of the HEC/urea/formamide separation matrix. Line (15) and line (25) represent the peak spacing and peak width, respectively, of the prior art matrix. 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:
An LED point imaging scanner for stimulating and reading fluorescent and reflective signal radiation from a target sample (10) is disclosed. LED light source (12) is mounted on scan head (20) and focused into pinhole aperture (15) of spatial filter (30), then collimated and focused to a spot (17) on sample (10). The spatial filter, or an optical fiber equivalent, effectively restricts the incoherent LED light and creates a point light source. Signal radiation from sample (10) is collected through scan head (20) and the returning light beam is collimated and focused onto detection means (40). A spatial filter (22) in the path of the returning beam may also be utilized. Detection means (40) is either a small detector directly mounted onto the scan head, or an end of an optical fiber which transmits the point image to a remotely-positioned stationary detector. The scan head is moved along one or two axes relative to the sample.
Abstract:
Provided is a coaxial illumination and collection laser scanning system designed to provide substantially uniform detection sensitivity across the field of view of an objective lens (27; 127) by reducing lateral chromatic aberrations at the expense of amplifying axial chromatic aberrations. Axial chromatic aberrations in the system are removed in the path of a retro-beam (31). A laser (18; 117, 118) is in optical communication with the objective lens. The laser (18; 117, 118) produces a collimated beam of coherent light (19; 119) that is directed by a scanner (25) through the objective lens (27; 127) to illuminate a raster of spots on the sample's surface (29), thereby stimulating a series of small regions of the sample to emit light.
Abstract:
A compact, movable scan head (10) has multiple scanning modalities, capable of high speed and high resolution scanning of a variety of samples (20). Stimulation and detection of storage phosphor screens and fluorescent samples (20) are preferably achieved with first and second channels (81, 82) in an optical path of a first side (11) of the scan head (10). The first side (11) preferably has a laser diode light source (14). Reading of reflective and transmissive signals is also possible. A third channel (83) is available in the optical path of a second side (12) of the scan head (10). The third channel preferably provides LED (32) point scanning and reading of fluorescent, reflective and transmissive signals received from the sample (20). The various modalities of the scan head (10) have coincident optical paths.
Abstract:
Composition, methods of synthesis and uses of a peptide-based moiety for oral drug delivery, having the general formula: [X-A]2 - [B]2 -1 - C, wherein X is an amino acid blocking group; A is selected from the group consisting of at least one amino acid; B is selected from the group consisting of lysine, ornithine and combinations thereof; C is selected from the group consisting of a free carboxyl group, or a protected carboxamide (CONH2); and n is the number of cycles of addition of B, including the addition of various xenobiotics and endogenous drugs.