Device for enumerating microorganisms

Patent metadata

Field	Value
Publication number	US-12053773-B2
Application number	US-201917056884-A
Country	US
Kind code	B2
Filing date	May 23, 2019
Priority date	May 29, 2018
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A microbial detection device and methods of use are provided. The device comprises a water-proof pouch that includes a first wall portion, a second wall portion, and a porous membrane filter disposed in the pouch between the first and second wall portions. The filter membrane divides the pouch into first and second compartments. A dry, cold water-soluble gelling agent is adhered to the pouch in the first compartment and an absorbent pad is disposed in the second compartment. A release liner removably adhered to the first adhesive layer.

First claim

The invention claimed is:

1. A microbial detection device, comprising:
a water-proof pouch comprising:
a first wall portion having an inner surface and an outer surface;
a second wall portion having an inner surface and an outer surface;

a porous membrane filter disposed in the pouch between the inner surface of the first wall portion and the inner surface of the second wall portion, the membrane filter having a first major surface and a second major surface opposite the first major surface;
a frame coupled to the membrane filter, the frame having a first major surface and a second major surface opposite the first major surface;
a first compartment defined in part by inner surface of the first wall portion and defined in part by the first major surface of the membrane filter and the first major surface of the frame;
a second compartment defined in part by the inner surface of the second wall portion and defined in part by the second major surface of the membrane filter and the second major surface of the frame;
a dry cold water-soluble gelling agent in the first compartment; and
an absorbent pad disposed in the second compartment;
wherein the membrane filter permits passage of aqueous liquids from the first compartment to the second compartment and prevents passage of particles of a predetermined size from the first compartment to the second compartment;
wherein the frame is coated on the first major surface with a first adhesive layer and on the second major surface with a second adhesive layer;
wherein the frame comprises an aperture through which liquid passes from the first compartment into the membrane filter;
a release liner removably adhered to the first adhesive layer, wherein part of the release liner faces the first wall portion.

2. The device of claim 1 , wherein the release liner is a J fold release liner.

3. The device of claim 1 , wherein the release liner comprises a edge and at least a portion of the edge has a slope that is oriented at an effective angle α between 10 degrees and 80 degrees with respect to the longitudinal axis of the release liner.

4. The device of claim 3 , wherein effective angle α is about 45 degrees.

5. The device of claim 1 , wherein the release liner comprises a tab for removal of the release liner from the microbial detection device.

6. The device of claim 1 , wherein the pouch comprises a deformable first wall portion disposed opposite the membrane filter in the first compartment.

7. The device of claim 1 , wherein the pouch comprises a deformable second wall portion disposed proximate the absorbent pad in the second compartment.

8. The device of claim 1 , wherein the membrane filter comprises a supported membrane.

9. The device of claim 1 , wherein the first wall portion or the second wall portion is fabricated from a flexible film.

10. The device of claim 1 , wherein the absorbent pad is coupled to the second wall portion or the absorbent pad is coupled to the frame.

11. The device of claim 1 , wherein the first compartment has a first maximum capacity, wherein the device is dimensioned to receive a liquid sample having a volume between 25 mL and 150 mL, inclusive.

12. The device of claim 1 , further comprising an indicator reagent for indicating a presence of a viable microorganism, wherein the indicator reagent is disposed in the pouch.

13. A method comprising:
placing a predetermined volume of aqueous sample into the first compartment of the device of claim 1 ;
removing the release liner;
sealing the device;
incubating the device for a period of time at a temperature that facilitates growth and detection of a target microorganism; and
detecting a presence or an absence of a colony of the target microorganism in the device.

14. The method of claim 13 , further comprising laying the outer surface of the first wall portion of the device or laying the outer surface of the second wall portion of the device onto a surface that is substantially perpendicular to gravitational force.

15. The method of claim 13 , further comprising passing at least 90% of the predetermined volume from the first compartment to the second compartment, wherein passing at least 90% of the predetermined volume comprises passing the volume by gravity force and/or capillary force.

16. The method of claim 13 , further comprising the step of combining the aqueous sample with a nutrient, nutrient medium, indicator reagent and/or selective agent prior to placing the predetermined volume into the first compartment.

17. The method of claim 13 , further comprising the step of combining the aqueous sample with a nutrient, nutrient medium, indicator reagent and/or selective agent after placing the predetermined volume into the first compartment.

18. The method of claim 13 , further comprising counting microbial colonies in the device.

Assignees

• 3M Innovative Properties Company

Inventors

• Young Alexi J
• Kruse John M
• Brown Christopher M
• Peterson Donald G
• Brutinel Evan D

Classifications

• C12Q1/04

  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 title

• B01L2300/123

  Flexible; Elastomeric · CPC title

• B01L2300/0887

  Laminated structure · CPC title

• B01L3/505

  Flexible containers without fluid transport within · CPC title

• B01L3/5023 Primary

  with a sample being transported to, and subsequently stored in an absorbent for analysis · CPC title