US4053362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bacterial isolation method and device
Assignee: Individual
•
Filing: 1976-04-02
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Granted: 1977-10-11
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Expires: 1996-04-02
Abstract
Abstract The present improved bacterial isolation device comprises a bacterial test container with closed bottom, raised sides and open top. A honeycomb type isolation grid providing a plurality of isolated cells is embedded in a layer of non-nutritive medium covering the bottom of the container, so that swarming types of bacteria cannot pass from one isolated cell to another and thus grow over bacteria to other isolated cells and mask them from detection. The improved method and device involve the disposition of a non-nutritive layer in the bottom of the container, covered with a separate layer of selected nutritive medium substantially unmixed therewith and introducing bacteria to the nutritive layer and embedding the isolation grid in the non-nutritive layer, covering the container and incubating the bacteria therein until they can be detected in the isolated grid cells. The method is simple, rapid, can be carried out with readily available, low-cost materials and eliminates both the requirements for a repeat test and for the use of bactericidal or bacteriostatic agents and the like in the nutritive medium to selectively suppress swarming bacteria.
Inventors
- 👤 Anthony Sforza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:30
CPC Classifications
C; C12; C12M; C12M23/00; C12M23/02; C12M23/10; C12M41/00; C12M41/30; C12M41/36
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
115 words
An improved bacterial isolation device comprising, in combination: a bacterial test container having a closed bottom, raised sidewalls and an open top; a layer of predetermined thickness of a bacterially non-nutritive medium covering said bottom, said medium being of an embeddable consistency; and an isolation grid comprising a first set of spaced walls intersected by and connected to a second set of spaced walls to form a plurality of isolated test cells, said grid having all its walls embedded in said medium, whereby during use of said device swarming bacteria are prevented from passing under said grid from one said isolated area to any other of said isolated areas to overlie and mask other bacteria.
Claim 2
Dependent Claim
115 words
An improved bacterial isolation device comprising, in combination: a bacterial test container having a closed bottom, raised sidewalls and an open top; a layer of predetermined thickness of a bacterially non-nutritive medium covering said bottom, said medium being of an embeddable consistency; and an isolation grid comprising a first set of spaced walls intersected by and connected to a second set of spaced walls to form a plurality of isolated test cells, said grid having all its walls embedded in said medium, whereby during use of said device swarming bacteria are prevented from passing under said grid from one said isolated area to any other of said isolated areas to overlie and mask other bacteria.
Claim 3
Dependent Claim
28 words
The improved device of claim 1 wherein said non-nutritive medium is bacterially non-nutritive and comprises a wax which is liquid at elevated temperature but solid at ambient temperature.
Claim 4
Dependent Claim
13 words
The improved device of claim 2 wherein said nonnutritive medium includes petroleum jelly.
Claim 5
Dependent Claim
18 words
The improved device of claim 3 wherein said non-nutritive medium comprises a mixture of paraffin and petroleum jelly.
Claim 6
Dependent Claim
26 words
The improved device of claim 1 wherein said grid comprises a honeycomb section and wherein said grid substantially fills an area defined by said container sidewalls.
Claim 7
Dependent Claim
14 words
The improved device of claim 1 wherein said device includes a detachable cover plate.
Claim 8
Dependent Claim
31 words
The improved device of claim 6 wherein said grid is releasably connected to the underside of said cover plate and is embedded in said non-nutritive medium to only a predetermined depth.
Claim 9
Dependent Claim
13 words
The improved device of claim 1 wherein said container comprises a Petri dish.
Claim 10
Dependent Claim
17 words
The improved device of claim 8 wherein the bottom of said Petri dish is irregular and non-planar.
Claim 11
Dependent Claim
115 words
The improved method of isolating bacteria for test purposes, said method comprising: disposing a layer of embeddable bacterially non-nutritive medium in a bacterial test container so as to fully cover the bottom of said container to a predetermined depth; covering said layer of non-nutritive medium with a separate layer of desired bacterial nutritive medium; adding bacteria to the top of the nutritive medium; embedding the bottom of an isolation grid in said non-nutritive medium, the upper edge of said grid being above the level of said nutritive medium to define a plurality of isolated test cells; and covering said container and incubating bacteria therein until the bacteria can be detected in said isolated test cells.
Claim 12
Dependent Claim
115 words
The improved method of isolating bacteria for test purposes, said method comprising: disposing a layer of embeddable bacterially non-nutritive medium in a bacterial test container so as to fully cover the bottom of said container to a predetermined depth; covering said layer of non-nutritive medium with a separate layer of desired bacterial nutritive medium; adding bacteria to the top of the nutritive medium; embedding the bottom of an isolation grid in said non-nutritive medium, the upper edge of said grid being above the level of said nutritive medium to define a plurality of isolated test cells; and covering said container and incubating bacteria therein until the bacteria can be detected in said isolated test cells.
Claim 13
Dependent Claim
20 words
The improved method of claim 10 wherein said bacteria are already in said nutritive medium when introduced into said container.
Claim 14
Dependent Claim
20 words
The improved method of claim 11 wherein said isolation grid is embedded in said non-nutritive medium before said bacterial introduction.
Claim 15
Dependent Claim
33 words
The improved method of claim 10 wherein said non-nutritive medium is bacterially non-nutritive and comprises a wax which is readily sterilizable as a liquid at elevated temperature but is solid at ambient temperature.
Claim 16
Dependent Claim
12 words
The improved method of claim 13 wherein said medium includes petroleum jelly.
Claim 17
Dependent Claim
18 words
The improved method of claim 14 wherein said non-nutritive medium comprises a mixture of paraffin and petroleum jelly.
Claim 18
Dependent Claim
41 words
The improved method of claim 10 wherein said non-nutritive and nutritive layers are kept substantially separate and unmixed so that channels of nutritive medium are not provided in said non-nutritive layer through which swarming bacteria can migrate between isolated grid areas.
References Cited (Backward Citations)
US3715280A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |