Abstract: An object of the present invention is to provide a method of measuring the amount of a compound containing a sugar chain in a biological sample by a sandwich immunoassay method using a labeled lectin, which method is suitable for reduction of noise originating from impurities and determination of the exact amount of a target compound. The present invention provides a method of measuring the amount of a target compound containing a sugar chain in a biological sample by a sandwich immunoassay method using a labeled lectin (including cases where a target compound-capturing substance other than an antibody is used as a ligand), the method containing adding a sugar chain compound which competes (crosses) with impurities contained in the biological sample in binding with the labeled lectin.

Abstract: A sheet feeding device having: a blowing device configured to blow air toward the stack of sheets placed in a predetermined stacking direction, thereby floating at least a top sheet from the stack; a suction/transportation mechanism that includes a suction belt provided above the mounting portion and configured to attract the top sheet floated by the blowing device to transport the attracted sheet in a predetermined transportation direction; and an image pickup device configured to capture images of the top sheet and the next sheet therebelow, and disposed so as to see through an area where a side of the top sheet and the suction belt, when viewed in a plan view in the stacking direction, are close to each other during the floating of the top sheet, to such an extent that the side of the top sheet essentially does not hang downward.