Eastman-kodak Company

Roger W Nelson

Richard C Sutton

Harold C Warren

Mitchell J Bogdanowicz

Brian A Snyder

Charles P Hagmaier

John Figueras

Edward G Bourne

A process for exposing dye imbibition printing matrix films is disclosed comprising imagewise exposing a matrix film comprising a visible light sensitive silver halide emulsion containing colloid layer on a support to blue, green or red light, wherein the visible light sensitive emulsion is also sensitive to UV light and the toe contrast of the imaged matrix film is controlled by (i) incorporating a UV absorber in the colloid layer of the matrix film, and (ii) flash exposing the matrix film with UV light in the substantial absence of light having a wavelength above 410 nm, wherein the UV absorber provides sufficiently low absorption above 410 nm such that it does not substantially alter the effective photographic speed of the matrix film during the imagewise exposure or the mid scale contrast of the imaged matrix film, and sufficiently high absorption to the UV light to decrease the resulting toe contrast of the imaged matrix film. In accordance with preferred embodiments of the invention, the above contrast control process is performed for each of the blue, green and red matrix films to be used in an imbibition printing process. The invention achieves desired toe contrast control of all three matrix films in the same manner. No longer does the blue matrix film require to be treated differently. This allows use of identical matrix films having blue, green and red sensitivity (e.g., a panchromatic sensitive film) in forming the separate blue, green and red exposed relief images if desired.

Curve shape control in a photographic imbibition dye transfer process

The invention is generally accomplished when a heavy metal compound and a substituted thiourea sensitizer are used together as chemical sensitizers. There is a surprising increase in photographic efficiency and, therefore, in photographic sensitivity. This effect does not depend on the presence of a dye. The preferred heavy metal compound is potassium hexachloroiridate (IV), and the preferred thiourea is 3-acetamidophenyl thiourea.

Silver halide emulsion sensitized with a heavy metal compound and a

There is disclosed a filter and a device positioning the filter between an upper and a lower chamber, particularly useful in an immunoassay. The filter and device are improved in that the membrane comprising the filter is overcoated with at least one water-soluble polymer of a type, a molecular weight, and at a dry-solids coverage effective to create for that membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.

Test device containing an immunoassay filter with a flow-delaying polymer

A membrane structure useful in filtration and diagnostic tests includes a microporous membrane formed from a biologically inert material, such as a polyamide, and has a coating comprising one or more water-soluble proteins or carbohydrates. None of the proteins and carbohydrates in the coating has a pI greater than about 5. The membrane structure is prepared by contacting the microporous membrane with the appropriate protein or carbohydrate in an amount sufficient to provide a coating over the entire membrane surface without substantially diminishing the porosity of the membrane. The membrane structure is useful in various diagnostic test procedures, such as agglutination assays.

Membrane structure coated with low pI protein or carbohydrate and

Methods, compositions and elements for detecting a nitrogen-containing compound capable of releasing ammonia upon enzymatic action are described. The method comprises contacting in an aqueous medium a sample suspected of containing such a compound and a novel assay composition comprising at least one enzyme which catalyzes the decomposition of the compound to ammonia and detecting the ammonia by condensation with a diketone and measuring the color or fluorescence produced by the resulting dihydropyridine. The foregoing assay composition can be incorporated into single-layer or multilayer analytical elements of the type known in the prior art. A preferred such element comprises an isotropically porous spreading layer in fluid contact with a reagent layer. The spreading layer is most preferably non-fibrous.

Method, composition and element for the detection of nitrogen-containing

A radiation-sensitive element comprises a support having thereon a composition comprising a depolymerizable polymer, such as a polymer of an aromatic 1,2-dialdehyde, and may also contain a radiation-sensitive substance or combination of substances, binder and/or a color-forming substance or combination of substances. A negative-working radiation-sensitive process comprises exposing a radiation-sensitive element to radiation, following which the element is heated in order to accelerate the depolymerization reaction. A visible image can be formed during heating by the reaction of the released monomer, such as an aromatic 1,2-dialdehyde, with a color-forming substance included in the element or contained in a separate element, or by heat treatment in the presence of a gaseous color-forming reagent. A positive-working radiation-sensitive process comprises exposing a radiation-sensitive element to radiation following which the element is heated or contacted with a solvent which removes the exposed areas but permits the unexposed areas to remain as a positive resist.

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Fairport, NY, United States of America

Roger W Nelson