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: 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.