Patent ID: 8258269

Claim:
A method for producing soluble thrombomodulin substantially not containing a denatured product of the soluble thrombomodulin that may be generated from the soluble thrombomodulin under acidic conditions, which comprises in the following order: (1) a step of leaving the soluble thrombomodulin-containing material under acidic conditions of pH 5 or less in its entirety for 1 hour or more prior to loading said soluble thrombomodulin-containing material to an anion exchanger or hydroxyapatite; and (2) the step of subjecting said soluble thrombomodulin-containing material that contains or is suspected to contain a denatured product of the soluble thrombomodulin from step 1 to an anion exchanger or hydroxyapatite, thereby obtaining a soluble thrombomodulin-containing fraction that does not substantially contain a denatured product of the soluble thrombomodulin.