Sterilization indicators including a neutralizer and methods

Abstract

Sterilization indicators that include a neutralizer, such indicators useful for testing the effectiveness of a sterilization procedure by measuring the activity of an active enzyme whose activity is correlated with the survival of microorganisms.

What is claimed: 
     
         1 . A method for testing the effectiveness of a sterilization procedure, the method comprising:
 providing a sterilization indicator comprising:
 a carrier; 
 biological material comprising a source of an active enzyme, wherein the source of active enzyme is supported by the carrier; wherein the active enzyme has an enzyme activity that is correlated with the survival of at least one test microorganism commonly used to monitor the effectiveness of a sterilization procedure; wherein the source of an active enzyme is inactivated by a sterilization procedure that is lethal to the test microorganism, but wherein the source of an active enzyme is not inactivated by a sterilization procedure that is sublethal to the test microorganism; 
 wherein one or more components of the sterilization indicator retains residual oxidizing sterilant; 
 a neutralizer disposed within the indicator in an amount effective to neutralize residual oxidizing sterilant, wherein the neutralizer is not an enzyme and not a metal catalyst; and 
 an enzyme substrate that reacts with the active enzyme to form an enzyme-modified product, which has a detectable signal, upon failure of a sterilization procedure; 
   subjecting the source of active enzyme to a sterilization procedure;   combining the enzyme and the substrate to form an enzyme-modified product;   determining whether the enzyme-modified product, which has a detectable signal, is present or absent; and   correlating the presence of the detectable signal with failure of the sterilization procedure and the absence of the detectable signal with success of the sterilization procedure.   
     
     
         2 . The method of  claim 1 , wherein the sterilization indicator is a dual rapid-readout indicator and the source of active enzyme comprises spores of a microorganism that serve as both the source of active enzyme for the enzyme activity test, and the test microorganism for the spore outgrowth test. 
     
     
         3 . The method of  claim 1 , wherein the sterilization procedure uses hydrogen peroxide vapor.