Abstract: Bacterial endotoxin in an assay sample is determined by an amoebocyte lysate component of horseshoe crab in the presence or absence of a substrate for endotoxin determination by using an assay sample in the liquid state obtained by treating said assay sample with an endotoxin-free acid having a pKa.sup.25.degree. C. value of not more than 3 at a pH of not more than 3; and a kit therefor, a receptacle containing (a) an endotoxin-free acid having a pKa.sup.25.degree. C. value of not more than 3 e.g. perchloric acid, trichloroacetic acid, nitric acid, for treating the assay sample and a receptacle containing (b) an amoebocyte lysate component or horseshoe crab. The acid treatment of the assay sample results in improved accuracy, reliability and reproducibility of the bacterial endotoxin determination.

Abstract: A method for extracting and collecting kallidinogenase (EC 3.4.4.21 substance) which comprises extracting the pancreas of a mammal with water in the presence of a salt at a temperature of about 45.degree. to about 60.degree. C. and a pH of about 5 to about 8, wherein the extraction is carried out in the presence of a water-soluble salt of magnesium with an acid, and a method for purifying kallidinogenase which comprises subjecting the aqueous phase of a kallidinogenase-containing aqueous extract obtained from the pancreas of a mammal to an adsorption-elution treatment using an anion-exchange resin, wherein said aqueous phase of the kallidinogenase-containing aqueous extract is brought into contact with a gel-type weakly basic anion-exchange resin to cause the kallidinogenase fraction to be adsorbed to said resin, and the kallidinogenase is eluted with an aqueous solution of an ammonium salt of a weak acid, thereby to collect the kallidinogenase.

Abstract: A method for extracting and collecting kallidinogenase (EC 3.4.4.21 substance) which comprises extracting the pancreas of a mammal with water in the presence of a salt at a temperature of about 45.degree. to about 60.degree. C. and a pH of about 5 to about 8, wherein the extraction is carried out in the presence of a water-soluble salt of magnesium with an acid, and a method for purifying kallidinogenase which comprises subjecting the aqueous phase of a kallidinogenase-containing aqueous extract obtained from the pancreas of a mammal to an adsorption-elution treatment using an anion-exchange resin, wherein said aqueous phase of the kallidinogenase-containing aqueous extract is brought into contact with a gel-type weakly basic anion-exchange resin to cause the kallidinogenase fraction to be adsorbed to said resin, and the kallidinogenase is eluted with an aqueous solution of an ammonium salt of a weak acid, thereby to collect the kallidinogenase.