Patent US5364766A successfully refreshed from Google Patents.
US5364766A
Expired / Lapsed
US
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Culture medium for rapid count of coliform bacteria
Assignee: 3M Co
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Filing: 1993-05-14
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Granted: 1994-11-15
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Expires: 2013-05-14
Abstract
Abstract This invention generally relates to products and processes used to determine the presence of bacteria in a sample and particularly relates to a culture medium which may be used in products and processes to allow early detection and count of coliform bacteria. The bacterial culture medium which facilitates the early detection and count of coliform bacteria is a mixture of tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red sufficient to provide a high concentration of phenol red in close proximity to the growing bacteria in order to allow detection and count of the growing bacteria in less than 12 hours.
Inventors
- 👤 Patrick A. Mach
- 👤 Karen E. Hesselroth
- 👤 Carl A. Adams
- 👤 Debra L. Schwab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:56
CPC Classifications
C; C12; C12N; C12N1/00; C12N1/20; C12M; C12M23/00; C12M23/02; C12M23/04; C12M23/22; C12M23/26; C12M23/38; C12M25/00; C12M25/06; C12M41/00; C12M41/30; C12M41/36; C12Q; C12Q1/00; C12Q1/02; C12Q1/04; C12Q1/045; Y; Y10; Y10S; Y10S435/00; Y10S435/81; Y10S435/8215; Y10S435/822; Y10S435/848; Y10S435/849
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
66 words
A bacterial culture medium which facilitates the early detection and count of coliform bacteria growing in the medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red sufficient to provide a high concentration of phenol red in close proximity to the growing bacteria in order to allow detection and count of the growing bacteria in less than 12 hours.
Claim 2
Dependent Claim
66 words
A bacterial culture medium which facilitates the early detection and count of coliform bacteria growing in the medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red sufficient to provide a high concentration of phenol red in close proximity to the growing bacteria in order to allow detection and count of the growing bacteria in less than 12 hours.
Claim 3
Dependent Claim
24 words
The culture medium of claim 1 wherein the concentration of phenol red is in the range of about 160 mg/l to about 5000 mg/l.
Claim 4
Dependent Claim
23 words
The culture medium of claim 1 wherein the concentration of phenol red is in the range of about 1000 mg/l about 5000 mg/l.
Claim 5
Dependent Claim
13 words
The culture medium of claim 1 wherein the medium further comprises triphenyltetrazolium chloride.
Claim 6
Dependent Claim
35 words
The culture medium of claim 4 containing about 10-20 g/l tryptose, 2.5-7.5 g/l lactose, 2.5-7.5 g/l sodium chloride, 1.35-1.65 g/l bile salts, 2.5-7.5 g/l guar gum, 0.025-0.120 g/l triphenyltetrazolium chloride, and 0.16-5.0 g/l phenol red.
Claim 7
Dependent Claim
35 words
The culture medium of claim 1 containing about 15 g/l tryptose, 5 g/l lactose, 5 g/l sodium chloride, 1.5 g/l bile salts, 5 g/l guar gum, 0.050 g/l triphenyltetrazolium chloride and 1.25 g/l phenol red.
Claim 8
Independent Claim
90 words
A method of detecting the presence of coliform bacteria in a sample comprising the steps of adding an aliquot of the sample containing coliform bacteria to a culture medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red sufficient to provide a high concentration of phenol red in close proximity to the bacteria; growing the bacteria in the presence of the culture medium; and detecting the color change of the phenol red as the growing bacteria metabolize in less than about 12 hours.
Claim 9
Independent Claim
90 words
A method of detecting the presence of coliform bacteria in a sample comprising the steps of adding an aliquot of the sample containing coliform bacteria to a culture medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red sufficient to provide a high concentration of phenol red in close proximity to the bacteria; growing the bacteria in the presence of the culture medium; and detecting the color change of the phenol red as the growing bacteria metabolize in less than about 12 hours.
Claim 10
Dependent Claim
16 words
The method of claim 7 wherein the bacteria are grown in agar containing the culture medium.
Claim 11
Dependent Claim
16 words
The method of claim 7 wherein the bacteria are grown in a suspension containing the medium.
Claim 12
Dependent Claim
43 words
The method of claim 9 wherein the bacteria are grown in a thin film containing the medium using a device having a self-supporting, waterproof substrate and a transparent cover sheet, wherein the culture media is coated on the waterproof substrate and then dried.
Claim 13
Dependent Claim
16 words
The method of claim 7 wherein the color change of the phenol red is detected visually.
Claim 14
Dependent Claim
18 words
The method of claim 7 wherein the color change of the phenol red is detected by an instrument.
Claim 15
Dependent Claim
13 words
The method of claim 7 wherein the culture medium further comprises triphenyltetrazolium chloride.
Claim 16
Dependent Claim
30 words
The method of claim 13 further comprising the step confirming the presence of coliform bacteria in the sample by detecting gas formation and a color change in the triphenyltetrazolium chloride.
Claim 17
Independent Claim
83 words
A device to detect coliform bacterial growth in a sample consisting essentially of a self-supporting, waterproof substrate, a foam spacer and a transparent cover sheet, wherein a culture medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red is coated on the self-supporting, waterproof substrate sufficient to provide a high concentration of phenol red in close proximity of growing bacteria in order to allow detection and count of the growing bacteria in less than 12 hours.
Claim 18
Independent Claim
83 words
A device to detect coliform bacterial growth in a sample consisting essentially of a self-supporting, waterproof substrate, a foam spacer and a transparent cover sheet, wherein a culture medium comprising tryptose, lactose, sodium chloride, bile salts, guar gum and an excess amount of phenol red is coated on the self-supporting, waterproof substrate sufficient to provide a high concentration of phenol red in close proximity of growing bacteria in order to allow detection and count of the growing bacteria in less than 12 hours.
Claim 19
Dependent Claim
23 words
The device of claim 15 wherein the phenol red changes color from red to yellow and wherein the color change is detected visually.
Claim 20
Dependent Claim
25 words
The device of claim 15 wherein the phenol red changes color from red to yellow and wherein the color change is detected by an instrument.
Claim 21
Dependent Claim
13 words
The device of claim 15 wherein the culture medium further comprises triphenyltetrazolium chloride.
Claim 22
Dependent Claim
21 words
The device of claim 18 wherein the triphenyltetrazolium chloride changes color in the presence of coliform bacteria after about 24 hours.
References Cited (Backward Citations)
US3960658A
Cited
US4335205A
Cited
US4565783A
Cited
US4416984A
Cited
US4906565A
Cited
US5073488A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |