Abstract: A process for differentially determining .alpha.-amylase isoenzyme activities by the inhibitor method, in which 6.sup.3 -deoxymaltotriose (DOG3) represented by the formula ##STR1## is used as an inhibitor.

Abstract: A batch method for preparing polyacrylamide aqueous gels for electrophoresis, including providing a plurality of gel plate supporters abreast in an airtight gel-forming container, eliminating oxygen from or introducing oxygen-free gas into said container, charging a gel-forming solution into said container, and gelatinizing the solution. It can easily produce a large quantity of high quality polyacrylamide gel plates for electrophoresis with a homogeneous quality and a high resolving power in an automated batch method in a short period of time.

Abstract: A process for preparing a polyacrylamide gel plate for electrophoresis with any desired concentrations, which comprises mixing a high concentration acrylamide monomer solution, a low concentration peroxide solution, and a low concentration reducing solution at an arbitrary ratio, and introducing the mixture into a gel supporter. The process enables preparation of a large quantity of high quality polyacrylamide gel plates for electrophoresis which is useful for analysis of high molecular weight in vivo components typified by proteins with a good reproducibility. It also contributes to the production of various gels having a plurality of gel concentrations or having a specified concentration gradient, and serves for improving the productivity of multi-products manufacturing of such gel plates.

Abstract: The present invention provides a maltooligoside derivative represented by the formula: ##STR1## wherein n denotes an integer 3-5, R represents an aromatic chromophoric group, X represents a group >CHCH.sub.2 N.sub.3 or >C.dbd.CH.sub.2, and Y represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group or an alkyl- or arylsulfonyl group, a reagent for determining .alpha.-amylase activity which comprises said maltooligoside derivative as an effective ingredient, and a process for determining .alpha.-amylase activity, characterized in that said maltooligoside derivative and coupled enzymes are added to an .alpha.-amylase containing sample to conduct an enzymatic reaction and a liberated aromatic chromophoric compound is quantitatively determined. The compound of the present invention is very useful as a substrate for determining .alpha.-amylase activity, and .alpha.

Abstract: Disclosed herein is an improved method for measurement of serotonin uptake sites in a sample, in which a radioligand is incubated with a sample and then the radioactivity of the radioligand bound to the sample is determined, wherein the improvement comprises using tritium-labeled 6-nitro-2-N-piperazinylquinoline or an acid addition salt thereof as the radioligand.

Abstract: A quantitative analysis of 3-oxo-5.beta.-steroid is carried out by acting 3-oxo-5.beta.-steroid.DELTA..sup.4 -dehydrogenase on a sample in the presence of a reducing chromophoric agent, and measuring the optical density of the chromophoric substance thereby produced. A typical reducing chromophoric agent is a tetrazolium compound. The invention also provides a reagent for the quantitative analysis of 3-oxo-5.beta.-steroid comprising 3-oxo-5.beta.-steroid.DELTA..sup.4 -dehydrogenase and a tetrazolium compound. The analysis and reagent provide a simple and reliable method for a liver function test.

Abstract: An improved silver staining technique is disclosd for the detection of a biocomponent contained in a support medium. The technique includes fixing the support medium with a fixing agent, pretreating the thus-fixed support medium with a sensitizer, treating the resultant support medium with a silver staining solution and then developing the thus-treated support medium with a reducing agent. In one aspect of the invention, thiourea is incorporated in either one or both of the fixing agent and sensitizer. In another aspect of the invention, thiosulfate is contained in the reducing agent. According to the invention, improved stainability and contrast are obtained. Also disclosed is a silver staining kit.

Abstract: An immunoassay making use of latex agglutination is practized by providing a colored latex as a latex, subjecting the colored latex to an immune reaction to form agglutinated particles of the colored latex, capturing the particles by means of a thin membrane with capillary-shaped pores formed therethrough, and then measuring the amount of the agglutinated particles thus captured.

Abstract: A method for quantitative analysis of hydrogen peroxide at a high precision is disclosed. The method comprises reacting a divalent cobalt compound with hydrogen peroxide in the presence of peroxidase or a substance similar to peroxidase to produce a trivalent cobalt compound, reacting the trivalent cobalt compound thus produced with a trivalent cobalt indicator to produced a colored complex, and subjecting the colored complex to colorimetric quantitative analysis. The method enables various enzymatic activities producing hydrogen peroxide by the reaction with substrates as well as the amount or activity of substances involving the known enzymatic reactions linked with such enzymatic reactions, of enzymes and coenzymes, to be quantitatively determined very easily at a high sensitivity at a wavelength of above 600 nm without the interference of hemoglobin, bilirubin, or turbidity.

Abstract: Disclosed herein is a physiologically-active peptide represented by the following general formula (I): ##STR1## wherein X means H or H-Asp-Ser-Gly- and Y denotes -Asn-Val-Leu-Arg-Arg-Tyr-OH, -Asn-Val-Leu-Arg-Arg-OH, -Asn-Val-Leu-Arg-Tyr-OH, -Asn-Val-Leu-Arg-OH, -Asn-Val-Leu-OH or -Asn-Ser-Phe-Arg-Tyr-OH, or a salt thereof.

Abstract: Disclosed herein is a 3.alpha.-hydroxysteroid oxidase which oxidizes a 3.alpha.-hydroxysteroid into a 3-oxosteroid and hydrogen peroxide. The oxidase may preferably be obtained from a culture broth of Pseudomonas testosteroni (ATCC 11996). The oxidase is useful for the quantitative analysis of a 3.alpha.-hydroxysteroid. Method and reagent useful for the quantitative analysis of a 3.alpha.-hydroxysteroid are also disclosed.

Abstract: A 3.alpha.-hydroxysteroid contained in a sample can be quantitatively analyzed by causing a 3.alpha.-hydroxysteroid dehydrogenase to act on the sample in the presence of nicotinamide adenine dinucleotide, causing tetrazolium or a salt thereof, an electron carrier substance, and 3-oxosteroid-.DELTA..sup.1 -dihydrogenase and/or 3-oxosteroid-.DELTA..sup.4 -dehydrogenase to act on the thus-obtained reaction product, and then quantitatively analyzing the resultant formazan.

Abstract: A novel vertical slab type electrophoresis apparatus, characterized by the provision of a gel holding glass sheet couple detachably fitted in a pair of tapered fitting groove formed opposingly on and along the entire length of glass support column portions of a buffer solution chamber by means of wedge-like fixing bars having an outer shape corresponding to the internal wall shape of said fitting groove.The electrophoresis apparatus precludes distortion of the gel which is gripped between the coupled glass sheets, permitting to obtain excellent migration images while preventing fracture of the glass sheets.

Abstract: A component of a sample may be detected or quantitatively measured by an immunoreaction, namely causing a target substance-immunoreactive reagent labelled with a marker-reaction product and/or any remaining, unreacted, immunoreactive reagent to move while making use of capillarity, causing the reaction product or any remaining, unreacted, immunoreactive reagent to combine with a substance packed in a capillary tube, and is immobilized on a carrier and adapted to uptake labelled substance so as to immobilize the reaction product or any remaining, unreacted, immunoreactive reagent, and measuring the amount of the thus-immobilized labelled substance. Since reagents are all filled in the capillary tube, there is no such troublesome that the reagents have to be prepared and/or any extra reagents have to be discarded upon conducting the measurement. The immunoassay may be carried out at bed side in hospitals. An extremely small amount of the sample may be sufficient for its measurement.

Abstract: In an immunoassay, ultrafine particles having an average particle size of 0.2 .mu.m or smaller and sensitized with a substance, which has reactivity with the materials to induce a nonspecific immunoreaction, are added to a sample to inhibit the nonspecific immunoreaction. The above immunoassay can avoid the influence of nonspecific factors more effectively, thereby permitting accurate measuremens on the concentrations of antigens in samples such as blood, urine, body fluid and the like.

Abstract: A silver staining method comprising the steps of (1) pretreating a carrier bearing thereon a substance to be detected with an alcoholic solution containing polyethylene glycol or polyoxyethylene alkylphenol, and (2) treating the pretreated carrier with a solution comprising silver nitrate, a compound of R--NH.sub.2, and a caustic alkali in ratios by molecular weight of 1:4.5-9.5:1.0-26.0.The method according to the invention involves advantages of high sensitivity and good reproducibility of detection, simple operation, safe handling etc.