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US4087326A Expired / Lapsed US ⏱️ 0.0 years remaining

Microbiological scaled sterility test strips and method

Assignee: Ethicon Inc
•
Filing: 1976-05-03
•
Granted: 1978-05-02
•
Expires: 1996-05-03
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Abstract

Abstract A method and apparatus for obtaining a permanent visual record of the microbiological effectiveness of a sterilizing cycle is provided by a spore carrier strip having a plurality of individual spore colony sites defined on the surface thereof, each of said sites containing a different population of spores, as for example, 10 2 , 10 3 , 10 4 , 10 5 , and 10 6 . The spore carrier is exposed to the sterilizing cycle, then incubated in a sterile nutrient culture medium containing a color indicator for viable microorganisms such as 2,3,5-triphenyl tetrazolium chloride. The development or lack of development of color on each spore colony site of successively increasing spore populations indicates the degree of effectiveness of the sterilizing cycle. The developed color is permanent and the carrier strip may be retained to provide a permanent visual record of the effectiveness of the sterilizing cycle.

Inventors

  • 👤 Karl Kereluk

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 05:33
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/02; C12Q1/22; C12M; C12M37/00; C12M41/00; C12M41/30; C12M41/36; G; G01; G01N; G01N31/00; G01N31/22; Y; Y10; Y10S; Y10S435/00; Y10S435/805; Y10S435/81

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 102 words
A method for providing a permanent record of the effectiveness of a sterilizing cycle which comprises (a) providing a sterility test strip comprising a single carrier having a plurality of individual microorganism colony sites defined on the surface thereof, each of said sites containing a different population of microorganisms, (b) exposing said sterility test strip to the sterilizing cycle and (c) incubating said colony sites on said exposed test strip in a common culture medium containing a viable microorganism color indicator whereby the effectiveness of the sterilizing cycle is indicated by the degree of color development on the individual microorganism colony sites.
Claim 2
Independent Claim 102 words
A method for providing a permanent record of the effectiveness of a sterilizing cycle which comprises (a) providing a sterility test strip comprising a single carrier having a plurality of individual microorganism colony sites defined on the surface thereof, each of said sites containing a different population of microorganisms, (b) exposing said sterility test strip to the sterilizing cycle and (c) incubating said colony sites on said exposed test strip in a common culture medium containing a viable microorganism color indicator whereby the effectiveness of the sterilizing cycle is indicated by the degree of color development on the individual microorganism colony sites.
Claim 3
Dependent Claim 41 words
A method of claim 1 wherein the concentration of microorganisms in each colony site is equal to a real positive integer greater than zero raised to a real positive exponential integer, each of said exponential integers being different from the others.
Claim 4
Dependent Claim 21 words
A method of claim 2 wherein the population of microorganisms on said sites is from 10 2 to 10 6 .
Claim 5
Dependent Claim 15 words
A method of claim 1 wherein the viable microorganism color indicator is a tetrazolium salt.
Claim 6
Dependent Claim 12 words
A method of claim 4 wherein the color indicator is 2,3,5-tetrazolium chloride.
Claim 7
Dependent Claim 22 words
A method of claim 5 wherein the concentration of 2,3,5-triphenyl tetrazolium chloride in the culture medium is from about 0.0005 to 0.005%.
Claim 8
Dependent Claim 15 words
A method of claim 6 wherein the concentration of 2,3,5-triphenyl tetrazolium chloride is about 0.0025%.
Claim 9
Dependent Claim 25 words
A method of claim 1 wherein the exposed test strip is incubated in said culture medium for at least about 24 hours at 37° C.
Claim 10
Dependent Claim 13 words
A method of claim 1 wherein the culture medium is Trypticase Soy Broth.
Claim 11
Dependent Claim 13 words
A method of claim 1 wherein the microorganisms are spores of Bacillus subtilis.

References Cited (Backward Citations)

US3107204A Cited
US3341427A Cited
US3346464A Cited
US3711378A Cited
US3819490A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-05-01 1981-10-31 1982-05-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-05-01 1985-10-31 1986-05-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-05-01 1989-10-31 1990-05-02 $7700.00 Window Closed / Lapsed

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