US4026767A
Expired / Lapsed
US
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Test procedure for microorganisms in blood
Assignee: Wisconsin Alumni Research Foundation
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Filing: 1975-11-19
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Granted: 1977-05-31
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Expires: 1995-11-19
Abstract
Abstract A method for indicating the presence of microorganisms in blood or other fluids comprising introducing the material to be tested into a nutrient medium containing a ditetrazolium chloride which converts to detectable blue color component in response to dehydrogenase reduction which takes place when microorganisms are present, incubating the said nutrient medium for a short period of time, and then examining the incubated product whereby a blue coloration is indicative of the presence of microorganisms in the sample.
Inventors
- 👤 Chun-Nan Shih
- 👤 Edward Balish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:25
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/02; C12Q1/04; C12Q1/26; C12Q1/32; C12Q2304/00; C12Q2304/20; C12Q2304/24
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
164 words
A method for indicating the presence of microorganisms in blood samples comprising introducing the blood into a nutrient medium having a pH within the range of 6.8 to 7.5 containing a ditetrazolium chloride which converts to a detectable blue color component in response to microbial dehydrogenase reduction which takes place when microorganisms are present in the blood, incubating the nutrient medium contained in the sample for a short period of time and then examining the incubated product to detect the presence of microorganisms as indicated by a blue color formed by reduction of the ditetrazolium chloride in which the ditetrazolium chloride has the general formula ##STR2## in which R 2 , R 2 ' , R 5 , R 5 ' are aromatic groups which may be substituted on the meta or para position with groups selected from the group selected from C 1 to C 5 alkoxy, nitro and halogen groups, R 3 is biphenylene or C 1 to C 5 alkoxy biphenylene.
Claim 2
Independent Claim
164 words
A method for indicating the presence of microorganisms in blood samples comprising introducing the blood into a nutrient medium having a pH within the range of 6.8 to 7.5 containing a ditetrazolium chloride which converts to a detectable blue color component in response to microbial dehydrogenase reduction which takes place when microorganisms are present in the blood, incubating the nutrient medium contained in the sample for a short period of time and then examining the incubated product to detect the presence of microorganisms as indicated by a blue color formed by reduction of the ditetrazolium chloride in which the ditetrazolium chloride has the general formula ##STR2## in which R 2 , R 2 ' , R 5 , R 5 ' are aromatic groups which may be substituted on the meta or para position with groups selected from the group selected from C 1 to C 5 alkoxy, nitro and halogen groups, R 3 is biphenylene or C 1 to C 5 alkoxy biphenylene.
Claim 3
Dependent Claim
38 words
A ditetrazolium chloride as claimed in claim 1 in which R 2 , R 2 ' , R 5 , R 5 ' are groups selected from the group consisting of phenyl, p-nitrophenyl, m-nitrophenyl, anisyl, piperonyl-3, and 3,4-dimethoxyphenyl.
Claim 4
Dependent Claim
16 words
A method as claimed in claim 1 in which the ditetrazolium chloride is 2,2',5,5'-tetraphenyl-3(3,3'-dimethoxy-4,4'-biphenylene) purple-ditetrazolium chloride.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 1 in which the ditetrazolium chloride is present in the nutrient medium in an amount of at least 0.0002 gram per 100 cc.
Claim 6
Dependent Claim
32 words
A method as claimed in claim 1 in which the ditetrazolium chloride is present in the nutrient medium in an amount within the range of 0.0005 to 0.02 gram per 100 cc.
Claim 7
Dependent Claim
22 words
A method as claimed in claim 1 in which the nutrient medium is sterilized prior to the addition of the ditetrazolium chloride.
Claim 8
Dependent Claim
34 words
A method as claimed in claim 1 in which the ditetrazolium chloride is added to the nutrient medium in the form of a solution which has been sterilized before addition to the nutrient medium.
Claim 9
Dependent Claim
23 words
A method as claimed in claim 1 in which the nutrient medium contains substrates which facilitate the enzymatic reduction of the ditetrazolium chloride.
Claim 10
Dependent Claim
24 words
A method as claimed in claim 8 in which the substrate is selected from the group consisting of a soluble succinate, lactate and isocitrate.
Claim 11
Dependent Claim
25 words
A method as claimed in claim 9 in which the substrate is present in an amount up to 1.2% by weight of the nutrient medium.
Claim 12
Dependent Claim
25 words
A method as claimed in claim 9 in which the substrate is present in an amount within the range of 0.1 to 1.2% by weight.
Claim 13
Dependent Claim
19 words
A method as claimed in claim 1 in which the nutrient medium is at a pH of about 7.2.
Claim 14
Dependent Claim
26 words
A method as claimed in claim 1 in which addition is made to the nutrient medium of a buffer composition to maintain the desired pH level.
Claim 15
Dependent Claim
21 words
A method as claimed in claim 1 in which the nutrient medium contains a carbohydrate as a source for additional hydrogen.
Claim 16
Dependent Claim
13 words
A method as claimed in claim 14 in which the carbohydrate is glucose.
Claim 17
Dependent Claim
136 words
A blood microorganism-detecting composition comprising a nutrient medium having a pH within the range of about 6.8 to 7.5 and capable of supporting the growth of microorganisms under incubating conditions, and which contains as an essential ingredient, a ditetrazolium chloride having the general formula of claim 1 which is characterized by the generation of a blue color when exposed to the dehydrogenase elaborated by growing microorganisms and is present in an amount within the range of 0.0002- 0.02 grams per 100 cc of medium, a substrate selected from the group consisting of a soluble succinate, lactate and isocitrate in an amount sufficient to trigger enzymatic reduction without chemical reduction of the ditetrazolium chloride in the absence of microorganism, and a buffer present in an amount to maintain the pH within the range of 6.8 to 7.5.
References Cited (Backward Citations)
US3496066A
Cited
US3928141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |