5407results about "Analysis using chemical indicators" patented technology

An analytical test device useful for example in pregnancy testing, comprises a hollow casing (500) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilized on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating means, such as an aperture (508) in the casing, enabling the extent (if any) to which the labelled reagent becomes bound in the second zone to be observed. Preferably the device includes a removable cap for the protruding bibulous member.

An apparatus and method for sealing a fluid sample collection device, comprising: loading a fluid sample collection device with a fluid sample, said device comprising a housing having at least one substantially planar surface that includes an orifice in fluid communication with an internal fluid sample holding chamber which terminates at an internal capillary stop; and slidably moving a sealing element over at least a portion of said substantially planar surface in a way that displaces any excess fluid sample away from the orifice, seals the fluid sample within said holding chamber, and inhibits the fluid sample from prematurely breaking through the internal capillary stop.

The present invention provides a method of measuring an analyte, such as glucose in a fluid sample, such as whole blood, by a reflectance reading device. The method includes making periodic intermediate calculations of analyte level and dynamically ascertaining when an analytical reaction has reached an end point. Once stable, the process stops making periodic calculations and reports the final, actual glucose concentration. According to an exemplary embodiment, the method is performed by a reflectance photometer using an analytical test strip containing reagents that react with an analyte of interest in the test fluid. The end point is determined by calculating an intermediate analyte level of the testing element at predetermined intervals and calculating a ratio value corresponding to the (n)th measurement to an (n-5)th measurement. When two consecutive ratio values are less than or equal to a predetermined value, the end point is deemed reached and the final analyte level ascertained.

Methods for high speed, high throughput analysis of polynucleotide sequences, and apparatuses with which to carry out the methods are provided in the invention.

An assay result reader, for use in conjunction with an assay device comprising a porous liquid-permeable carrier in the form of a strip or sheet through the thickness of which electromagnetic radiation is transmissible, the carrier including a detection zone in which an assay result is revealed by specific binding of a detectable material directly or indirectly to a binding agent immobilized in the detection zone, detection of the detectable material being effected by determining the extent to which electromagnetic radiation transmitted through the thickness of said carrier is attenuated by the presence of the detectable material bound in the detection zone.

Devices and methods are provided for performing a test to detect and / or quantify the presence of an analyte of interest within a sample using a portable instrument.

A test strip with a covering layer having a novel slot. The slot divides the inventive covering layer into two parts and provides a vent opening that allows air to escape as fluid enters a cavity or sample receiving chamber formed in the test strip. In preferred embodiments, the covering layer is clear such that the user can see through it and the slot doubles as a “fill line.” The user can thus watch the fluid sample enter the test strip, progress through the capillary cavity, and then stop at the slot or fill-line. This provides positive assurance to the user that the sample size is sufficient and the test strip has been filled properly. The present invention also provides an advantageous method of mass-producing the inventive test strips without having to align the slot or vent opening laterally with respect to the test strips and without having to punch a vent opening. The method is also well suited to mass production by roll processing techniques.

A method of measuring an analyte in a biological fluid comprises applying an excitation signal having a DC component and an AC component. The AC and DC responses are measured; a corrected DC response is determined using the AC response; and a concentration of the analyte is determined based upon the corrected DC response. Other methods and devices are disclosed.

A device that provides for both the collection of saliva and detection of at least one analyte therein, e.g., a drug, is provided. This device provides for rapid analysis of saliva samples, while also providing a convenient assay method that does not require the addition of extraneous reagents, or other materials. Thereby, this device can be used by non-laboratory personnel without risk of user introduced errors.

A three-dimensional microfluidic device (100) formed from a plurality of substantially planar layers (101, 102, 103) sealed together is disclosed

The present invention discloses microfluidic modules for making nanocrystalline materials in a continuous flow process. The microfluidic modules include one or more flow path with mixing structures and one or more controlled heat exchangers to process the nanocrystalline materials and reagents in the flow path. The microfluidic modules can be interconnected to form microfluidic reactors that incorporate one or more process functions such as nucleation, growth, and purification.

This invention relates to gas- or liquid-permeable materials that seal when exposed to water and methods of making such materials. In general, materials of this invention comprise a hydrogel adhered to pore walls of a porous substrate. The invention further relates to devices comprising self-sealing materials including, but not limited to, pipette tips, containers, intravenous liquid delivery systems, and syringe caps.

A test strip with a sample receiving chamber having a novel flared portion that terminates in a sample receiving opening. The flared portion provides a reservoir from which sample fluid can be drawn into the capillary or sample receiving chamber. The wider opening provided by the present invention is easier to “target” with a sample fluid. In preferred embodiments, the hydrophilic reagent layer extends to the dosing end or side of the test strip and further promotes wicking of the sample into the sample receiving chamber and thus reduces dose hesitation. In other preferred embodiments, a tapered dosing end is provided on the test strip in combination with the flared portion, and this combination create a test strip that will draw sample fluid into the sample receiving chamber regardless of where along the dosing edge of the test strip the fluid sample makes contact.