Pre-treatment agent and pre-treatment method for antithrombin iii to be subjected to limulus test

Abstract

To provide means for reducing reaction interference observed when AT III is subjected to limulus test, whereby the limulus test of antithrombin III can be carried out at high accuracy. Reaction interference observed when AT III is subjected to limulus test can be reduced by subjecting AT III to a protein inactivation treatment in the co-presence of a divalent metal salt.

1 . A pre-treatment method for antithrombin III to be subjected to  limulus  test, the method comprising subjecting antithrombin III to a thermal treatment or an acid treatment,
 wherein the thermal treatment and the acid treatment are conducted in the co-presence of a pretreatment agent which contains a divalent metal salt,   wherein antithrombin III is a pharmaceutical preparation of antithrombin III or a solution containing antithrombin III at a concentration of 50 Unit/mL or higher than 50 Unit/mL, and   wherein a target substance of the  limulus  test is endotoxin.   
     
     
         2 . The pre-treatment method according to  claim 1 , wherein the divalent metal salt is one or more metal salts selected from the group consisting of a divalent metal chloride, a divalent metal acetate, and a divalent metal sulfate. 
     
     
         3 . The pre-treatment method according to  claim 1 , wherein the divalent metal constituting the divalent metal salt is one or more metals selected from the group consisting of magnesium, calcium, manganese, and zinc. 
     
     
         4 . The pre-treatment method according to  claim 1 , wherein the concentration of the divalent metal ion derived from the divalent metal salt is 0.5 mM or higher when antithrombin III is co-present with the pre-treatment agent. 
     
     
         5 . The pre-treatment method according to  claim 1 , wherein the thermal treatment is performed at a temperature higher than 50° C. 
     
     
         6 . The pre-treatment method according to  claim 1 , wherein the acid employed in the acid treatment is hydrochloric acid. 
     
     
         7 . A method for measuring endotoxin contained in antithrombin III, the method comprising preliminarily treating antithrombin III through the pre-treatment method according to  claim 1 , and subjecting the preliminarily treated antithrombin III to  limulus  test. 
     
     
         8 . A method for producing antithrombin III, the method comprising measuring endotoxin in antithrombin III through the method according to  claim 7 .