Method for evaluating suitability of duodenal fluid sample as sample for detecting pancreatic fluid-derived components

A method for evaluating a suitability of a duodenal fluid sample as a sample for detecting pancreatic fluid-derived components, comprising:

• (a) mixing a duodenal fluid sample with a chymotrypsin-specific substrate and measuring an amount of degradation of the chymotrypsin-specific substrate by the duodenal fluid sample, the chymotrypsin-specific substrate having a cleavage site for chymotrypsin represented by the following general formula (1):
• —(Y1) n1- (X1) -Pro - (Y2) n2- (1)
• wherein, Y1 and Y2 respectively and independently represent an amino acid residue or —CH2—NH—,X1 represents Phe, Trp or Tyr, and n1 and n2 respectively and independently represent an integer of 1to 10,
• (b) mixing the duodenal fluid sample with a pepsin-specific substrate and measuring an amount of degradation of the pepsin-specific substrate by the duodenal fluid sample, the pepsin-specific substrate having a cleavage site for pepsin represented by the following general formula (2):
• —(Y3)n3-Pro-(X2)—(Y4)n4- (2)
• wherein, Y3and Y4 respectively and independently represent an amino acid residue or—CH2—NH—,X2represents Phe, Trp or Tyr, and n3and n4respectively and independently represent an integer of 1to10, and
• (c) evaluating that the duodenal fluid sample is suitable as a sample for detecting pancreatic fluid-derived components if the amount of degradation of the chymotrypsin-specific substrate by the duodenal fluid sample is higher than a first prescribed threshold and the amount of degradation of the pepsin-specific substrate by the duodenal fluid sample is lower than a second prescribed threshold, as being suitable as a sample for detecting pancreatic fluid-derived components.