World Precision Instruments, Inc.

Su Yi Liu

Purnendu K Dasgupta

Mathias Belz

Guo Chen Liu

Richard L Miller

A piston seal assembly for a pipette includes an O-ring having radially inner and outer surfaces and axially separated first and second surfaces. A seal includes a radially extending rim portion having axially separated first and second surfaces and an axially extending sleeve portion forming an opening. A seat includes an axially extending indexing portion and a radially extending engagement portion forming an opening and having axially separated first and second surfaces. The seal is positioned such that the pipette piston extends through the opening and the radially inner surface of the sleeve portion slidably engages the piston. The seat is positioned such that the piston extends through the opening, the first and second surfaces of the engagement portion engage the second surface of the rim portion and an end of the spring, respectively, and the radially outer surface of the indexing portion engages the inner surface of the pipette body. The O-ring is positioned such that the sleeve portion of the seal extends axially through the opening of the O-ring, the radially inner surface of the O-ring engages the radially outer surface of the sleeve portion, the radially outer surface of the O-ring engages the radially inner surface of the indexing portion, the first surface of the O-ring engages a shoulder of the pipette body, and the second surface of the O-ring engages the first surface of the rim portion.

Pipette piston seal assembly

A photometric detection system including a light source, a photometric detector, and a flow cell assembly. The flow cell assembly includes a tubular liquid core waveguide having inlet and discharge ends for receiving and discharging a flow of the sample fluid. A first coupling device optically couples the light source to the waveguide at a first position along the length of the waveguide. A second coupling device optically couples the detector to the waveguide at a second position along the length of the waveguide. The first and second positions define an optical path length within the waveguide. The second position is variable relative to the first position such that the optical path length is selectively varied.

Photometric detection system having multiple path length flow cell

The detection of a chemical specie of interest is accomplished by immobilizing sensing molecules on the inner wall of a liquid core optical waveguide, the waveguide comprising a capillary tube and the sensing molecules being selected to interact with the specie of interest carried by the liquid which forms the waveguide core. The interaction produces a change in an optical characteristic of the waveguide which may be detected by illuminating the waveguide with analysis light.

Optical analysis technique and sensors for use therein

A permeable optical fiber waveguide with a liquid core is employed as a probe for the detection or measurement of a chemical specie of interest by filling the waveguide core region with a light transmitting reagent liquid which undergoes a change in an optical characteristic thereof when exposed to the chemical specie and then inserting the filled waveguide into an environment in which the chemical specie may be present. The chemical specie, if present, will permeate through the waveguide wall and react with or be absorbed in the core liquid.

Chemical sensing techniques employing liquid-core optical fibers

A device for delivering precisely measured, minute quantities of liquid has no metal parts which contact the liquid. The device employs a barrel defining member with a bore which receives a polymer coated glass or ceramic fiber which functions as a piston. Fluid is drawn into and discharged from the bore via a needle in the form of a polymer coated glass or ceramic capillary tube.

Non-metallic precision fluid transfer devices

The chemical properties of a flowing liquid analyte, the analyte comprising a solvent having an index of refraction which is the same as or closely approaches that of water, are determined by liquid chromatography or capillary electrophoreses wherein the analyte is caused to flow through an optical waveguide. The waveguide is a rigid capillary having a refrctive index of less than 1.33. Measurement light is launched axially into the analyte by inserting an optical fiber, coupled to a light source, into one end of the waveguide.

Micro chemical analysis employing flow through detectors

Water or some other aqueous fluid is employed as the light transmitting medium of a liquid-core fiber-optic wave guide employed as a spectrophotometer cell by employing, to define the core region, a polymer having a refractive index of less than 1.33. The light conducting channel defined by the aqueous fluid filled core may be a capillary or other suitably shaped vessel. The analysis of samples is accomplished by drawing a sample into the wave guide core region throughout the use of a fiber optic piston and thereafter delivering measurement light to the sample via the piston.

Apparatus and method for measuring light absorption in small aqueous

Small quantities of liquid are conveyed, either for the purpose of filling micropipettes or to function as an electrolyte in an ion selective electrode, in a flexible non-metallic capillary tube which is mounted, at a first end, in an adapter fitting. The fitting defines a socket for coupling to a source of liquid, a hypodermic syringe for example, or for receiving an electrochemical half-cell which will contact an electrolyte in the tube. A filter may be interposed between the fitting and hypodermic syringe so as to frictionally engage both when the device is employed for filling micropipettes.

Growing community of inventors

Sarasota, FL, United States of America

Su Yi Liu