Abstract: A method for preparing a sample comprising a glycan includes: performing a lactonization reaction in which at least a part of sialic acids included in the glycan is lactonized; and performing an amidation reaction in which lactones of lactonized sialic acids are amidated through addition of an amidation reaction solution to the sample, the amidation reaction solution comprising at least one selected from the group consisting of ammonia, an amine, and a salt thereof that is reacted with the lactonized sialic acids.

Abstract: A method for evaluating the progression of hepatic fibrosis in non-alcoholic steatohepatitis, said method comprising measuring the amount of a sugar chain having a structure represented by formula (I) and/or a precursor sugar chain of the biosynthesis of a sugar chain having a structure represented by formula (I) in a sample.

Abstract: A method for preparing an analysis sample includes providing a sample containing a glycan, and performing an amidation reaction through contacting the sample with an amidation reaction solution having a pH of 7.7 or more, the amidation reaction solution containing at least one first compound which is to be reacted with a lactone included in the glycan, and which is selected from the group consisting of ammonia to be reacted with a lactone included in the glycan, primary amines having one or no carbon atom directly linked to a carbon atom linked to an amino group, hydrazine, hydrazine derivatives, hydroxylamine, and salts thereof, and alkalinizing agents to amidate the lactone, wherein when the alkalinizing agent is an amine, the alkalinizing agent is at least one amine selected from the group consisting of branched primary amines in which two or more carbon atoms are directly linked to a carbon atom linked to an amino group, secondary amines, and tertiary amines.

Abstract: A method for preparing an analysis sample from a sample containing a glycan, includes: performing esterification reaction that subjects at least a part of a sialic acid included in the glycan to esterification other than lactonization; and performing amidation reaction that converts an esterified form of a sialic acid modified through the esterification into an amidated form through contacting the sample with an amidation reaction solution containing at least one compound selected from the group consisting of ammonia, amines, hydrazine, hydrazine derivatives, and hydroxyamine, and salts thereof to be reacted with the sialic acid modified through the esterification.

Abstract: A method for preparing a sample comprising a glycan includes: performing a lactonization reaction in which at least a part of sialic acids included in the glycan is lactonized; and performing an amidation reaction in which lactones of lactonized sialic acids are amidated through addition of an amidation reaction solution to the sample, the amidation reaction solution comprising at least one selected from the group consisting of ammonia, an amine, and a salt thereof that is reacted with the lactonized sialic acids.