Abstract: The degree of a structure change of the sugar chain of a glycoprotein caused by a disease can be measured with high precision rapidly by separating and measuring two or more forms of glycoproteins which are different in sugar chain structure but have substantially the same protein structure, by using a combination of a lectin capable of recognizing the specific sugar chain structure of at least one of these glycoprotein analytes to be measured, and a first antibody which has a property of binding to all the glycoprotein analytes but is kept from binding to glycoprotein analyte(s) having the lectin attached thereto; and separating and measuring glycoprotein analyte(s) having the first antibody attached thereto and glycoprotein analyte(s) having no first antibody attached thereto, by utilizing differences in properties between the former glycoprotein analyte(s) and the latter glycoprotein analyte(s).

Abstract: This invention is intended to provide a process by which a complex formed by the interaction between one or more analytes to be measured and affinity substance can be more effectively separated from substances existing together therewith which tend to affect the detection of the complex, for example, free affinity substance, by using high pressure liquid chromatography (HPLC); and a process for measuring a trace component by utilizing said separating process.This invention is characterized in that a substance which has been modified with a substance capable of changing properties of the complex (a separation-improving substance) and has affinity for the complex is attached to the complex. Because of this characteristic, the invention is effective in that the position of elution of said complex in the HPLC can be freely controlled.

Abstract: The amount of an analyte in a sample derived from a living sample is measured by reacting the analyte with an excess of a substance having affinity for the analyte, followed by separation of complex by high pressure liquid chromatography and measurement using a linear calibration curve representing the peak area values associated with known concentrations of analyte.

Abstract: An oligosaccharide derivative of the formula: ##STR1## wherein R is --SR.sup.2, ##STR2## R.sup.1 is an optically detectable group, etc.; R.sup.2 is alkyl or substituted alkyl; and n is zero or 1-5, is effective as a substrate for measuring .alpha.-amylase activity and can be synthesized easily in high yield.

Abstract: .alpha.-Amylase activity can be determined rapidly and precisely by using as a substrate a modified oligo-saccharide wherein a benzylozymethyl group or a halo-methyl group is bonded to the C.sub.6 position of non-reducing-end glucose residue and the reducing-end glucose residue is bonded to a group which exhibits an optically measurable change upon cleavage. Processes for producing such a compound are also disclosed.

Abstract: .alpha.-Amylase activity can be determined rapidly and precisely by using as a substrate a modified oligosaccharide wherein a benzyloxymethyl group or a halomethyl group is bonded to the C.sub.6 position of non-reducing-end glucose residue and the reducing-end glucose residue is bonded to a group which exhibits an optically measurable change upon cleavage. Processes for producing such a compound are also disclosed.

Abstract: An oxidase selected from the group consisting of glycerol-3-phosphate oxidase, choline oxidase and glucose oxidase can be stabilized by adding thereto an acidic amino acid or a salt thereof. The resulting stabilized composition can be used for quantitatively determining the content of glycerol-3-phosphate, choline, triglyceride, glucose, etc., in a biological fluid.