Microbial detection article

• US 8,753,834 B2
• Filed: 12/30/2010
• Issued: 06/17/2014
• Est. Priority Date: 12/30/2009
• Status: Active Grant

• Current Assignee: Neogen Food Safety US Holdco Corporation (Neogen Corporation)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Miller, Jesse D., Moeller, Stephanie J., Halverson, Kurt J.
• Primary Examiner(s): Carlson, Karen Cochrane
• Assistant Examiner(s): Tichy, Jennifer M. H.
• Application Number:
  US13/519,284
• Publication Number:
  US 20120288888A1
• Time in Patent Office: 1,265 Days
• Field of Search: 435/34
• US Class Current: 435/34
• CPC Class Codes: C12M 23/20 Material Coatings immunocoatings C12M25/00
• CPC Class Codes: C12M 25/02 Membranes; Filters filters or filtration in general B01D24/00-B01D41/00
• CPC Class Codes: C12M 41/36 of biomass, e.g. colony counters or by turbidity measurements electrooptical investigation of individual particles G01N15/14, flow cytometers G01N15/1404
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence
• CPC Class Codes: C12Q 1/06 Quantitative determination
• CPC Class Codes: G01N 33/569 for microorganisms, e.g. protozoa, bacteria, viruses
• CPC Class Codes: G01N 33/56911 Bacteria

Abstract

The disclosure provides an article for the detection of a microorganism in a liquid sample. The article comprises a microporous membrane and a barrier layer to selectively regulate the contact between the sample and a detection reagent. A method of use is also provided.

Claims

1. A method of detecting the presence or absence of a microorganism in a sample, comprising:

providing,

a liquid sample suspected of containing a microorganism;

a detection article comprising;

a base member comprising a first dry coating that includes a cold water-soluble gelling agent;

a microporous membrane;

a cover sheet comprising a second dry coating that includes a first detection reagent;

a barrier layer that forms a fluid barrier between the microporous membrane and the cover sheet;

wherein the microporous membrane is disposed between the base member and the barrier layer;

contacting a predetermined amount of the sample with the first dry coating;

contacting the microporous membrane with the sample;

incubating the article for a first period of time;

repositioning the barrier layer to provide contact between the cover sheet and the microporous membrane;

incubating the article for a second period of time; and

observing an indication of the presence or absence of microbial growth.

2. The method according to claim 1, wherein repositioning the barrier layer comprises removing the barrier layer from the article.

3. The method according to claim 1, wherein the article further comprises a spacer that forms a sample-receiving well with the base member, wherein contacting a predetermined amount of the sample with the first dry coating comprises transferring the sample into the sample-receiving well.

4. The method according to claim 1, further comprising mixing the sample with a nutrient, a selective agent, a second detection reagent, or a combination of any two or more of the foregoing.

5. The method according to claim 1, wherein the first period of time is about 1 hour to about 48 hours.

6. The method according to claim 5, wherein the first period of time is about 4 hours to about 6 hours.

7. The method according to claim 1, wherein the second period of time is about 15 minutes to 96 hours or less.

8. The method according to claim 7, wherein the second period of time is about 15 minutes to about 6 hours.

9. The method according to claim 7, wherein the second period of time is about 2 hours to about 4 hours.

10. The method according to claim 1, wherein at least a portion of the first dry coating comprises a plurality of detection reagents, wherein observing an indication of microbial growth comprises detecting and differentiating two or more types of microorganisms.

11. The method according to claim 1, wherein observing an indication of the presence or absence of microbial growth comprises enumerating at least one type of microorganism.

12. The method according to claim 1, wherein observing an indication of the presence or absence of microbial growth comprises obtaining an image of the article.

13. The method according to claim 12, wherein observing an indication of the presence or absence of microbial growth further comprises printing, displaying, or analyzing the image.