In accordance with certain embodiments, a query from a client may be received at a server, and a default query range may be applied to the query. The stain composition is a staining agent which sharpens the shapes of digestive tract lumen surfaces and the like with a light in the visible wavelength range, having a function of being excited by a light of specific wavelength to emit fluorescence, and being biologically safe and suitable for endoscopy. When the cover is used alone it engages a frame or a wall circumscribing the access opening. The resistance element is elastically pre-stretched and then fixed at both ends to the press mechanism. The method involves adding, to a pancreatic juice-containing biological sample, at least one sulfonyl fluoride-containing protease inhibitor and at least one trypsin-like serine protease inhibitor belonging to a group of amino acid chloromethyl ketones.