Fuji Photo Film Company, Limited

Toshihisa Ito

Osamu Seshimoto

Kenichiro Yazawa

Takaki Arai

Masao Kitajima

Toshihiro Mori

Takashi Yoneyama

Yoshikazu Amano

Kazuko Hanai

Masaaki Terashima

Yoshiki Sakaino

Shigeru Tezuka

Takeshi Igarashi

Keiichi Ishizaki

Hitomi Ito

The immunoassay element for quantitatively analyzing an antigen by determining the change in enzymatic activity of an enzyme-labelled antigen or antibody caused by an immunological reaction. The immunoassay element comprises a substrate layer containing a non-diffusible substrate which forms a diffusible material in the presence of the labelling enzyme, and a reagent layer containing a fragmenting enzyme for further fragmenting the diffusible material into a lower molecular weight product. As the non-diffusible substrate, a substrate capable of reacting solely with the labelling enzyme and incapable of reacting the fragmenting enzyme is utilized. When an endo-active glucosidase is used as the labelling enzyme, and an exo-active glucosidase is used the fragmenting enzyme in the reagent layer, the non-diffusible substrate of the substrate layer is preferred to be an endo type selectively reactive substrate, which means a substrate having a reactivity specific to endo-active glucosidase. Highly sensitive assay is realized with high accuracy and high reproducibility and good storage stability.

Immunoassay element

A silver/silver halide electrode composed of a non-electroconductive support sheet, a silver metal layer and a silver halide layer in order, is improved in its sensitivity by making the silver halide layer almost free from heavy metal element, for instance, by oxidizing the silver metal layer on its surface side with an oxidizing compound containing no heavy metal element or a chelated ferric oxidizing compound in the presence of a halide containing no heavy metal element.

Method for producing a silver/silver halide electrode and ion-selective electrode element

A method for preparing a plasma or serum sample from a whole blood sample, by contacting a glass fiber filter which contains calcium, sodium or potassium components with an aqueous solution of an organic acid or a mineral acid to elute the calcium, sodium and potassium components in the glass fiber filter into the aqueous solution, separating the aqueous solution from the filter and washing the glass fiber filter with water to remove any residual aqueous solution adhered thereto and then filtering a whole blood sample through the thus treated fiber filter.

Method of preparing glass fiber filter

The invention provides a blood filter cartridge which is made so that the filtrate discharged from the filtrate outlet is not drawn back to the inside of the filtering chamber. The blood filter cartridge includes a blood filtering material, a holder containing the blood filtering material and having a blood inlet and a filtrate outlet, and a filtrate receiver which receives the filtrate discharged from the filtrate outlet. The blood filter catridge is provided with a means for preventing the filtrate in the filtrate receiver from returning to inside of the holder upon finishing filtration. Such means include the following: removing opposite faces around the filtrate outlet, making length of lower end of the filtrate outlet 0.8 mm or more, smoothing surface around the filtrate outlet, and forming surface around the filtrate outlet by a material having a small surface energy.

Blood filter cartridge

A magnetic recording medium comprising a nonmagnetic support having coated thereon a magnetic recording layer comprising a ferromagnetic particles dispersed in a binder, the binder containing polyisocyanate and the molar ratio of (urethane bond+allophanate bond):(urea bond+biuret bond) being 85:15 to 60:40.

Magnetic recording medium

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Saitama, Japan

Toshihisa Ito