Nutrient medium unit and method for holding a filter from a filtration device

Patent metadata

Field	Value
Publication number	US-10184101-B2
Application number	US-45019808-A
Country	US
Kind code	B2
Filing date	Feb 16, 2008
Priority date	Mar 21, 2007
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

The invention relates to a nutrient medium unit for holding a filter of a filtration device, comprising a lower part that is filled with the nutrient medium and a lid, the latter having a fixing edge that protrudes into the lower part and that can be connected to an edge of the filter by means of an adhesive bond in order to remove said filter from the filtration device. The invention also relates to a method for the microbiological analysis of liquid samples, according to which a membrane filter is lifted off a filter support and laid on the surface of a nutrient medium that is situated in a lower part of a nutrient medium unit. The lower part is then covered by a lid, the latter being placed on the membrane filter lying on the filter support in such a way that a fixing edge located in the lid is connected to an edge of the filter by means of an adhesive bond. The lid and the attached filter are lifted off the filter support and placed on the dish-shaped lower part of the nutrient medium unit.

First claim

The invention claimed is:

1. A nutrient medium unit ( 14 ) for holding a filter ( 4 , 4 ′) from a filtration device ( 1 ), the filter ( 4 , 4 ′) having opposite first and second surfaces and an outer peripheral edge ( 13 ) extending between the first and second surfaces, the nutrient medium unit comprising:
a lower part ( 15 , 15 ′) with a support ring and being filled with nutrient medium inward of the support ring;
a lid ( 16 ) having a top wall, an outer wall projecting from the top wall and telescoped over the lower part ( 15 , 15 ′) outward of the support ring, an annular inner wall ( 23 ) projecting from the top wall at positions inward of the outer wall, an end of the annular inner wall from the top wall and facing away from the top wall defining a fixing edge that is dimensioned to register with the first surface of the filter ( 4 , 4 ′) in proximity to the outer peripheral edge of the filter; and
an adhesive ( 22 , 27 ) applied to the end of the fixing edge ( 21 ) of the annular inner wall ( 23 ) and bonding the annular inner wall ( 23 ) to the filter ( 4 , 4 ′) in order to remove the filter from the filtration device, the annular inner wall ( 23 ) of the lid ( 16 ) projecting from the top wall thereof a sufficient distance so that areas of the second surface of the filter ( 4 , 4 ′) inward of the annular inner wall ( 23 ) contact the nutrient medium when the lid ( 16 ) is telescoped over the lower part ( 15 , 15 ′).

2. The nutrient medium unit of claim 1 , wherein the adhesive ( 22 ) is a temporary or reversible adhesive.

3. The nutrient medium unit of claim 1 , wherein the adhesive ( 27 ) is applied to the fixing edge ( 21 ) of the lid ( 16 ).

4. The nutrient medium unit of claim 3 , wherein the adhesive is applied to the fixing edge of the lid via a water-soluble intermediate layer ( 30 ).

5. The nutrient medium unit of claim 1 , wherein the adhesive ( 22 , 27 ) is applied to the first surface of the filter ( 4 , 4 ′) adjacent the outer peripheral edge ( 13 ) of the filter ( 4 ′).

6. The nutrient medium unit of claim 5 , wherein the fixing edge ( 21 ) of the lid ( 16 ) has a water-soluble layer ( 30 ).

7. The nutrient medium unit of claim 3 , wherein the adhesive ( 27 ) is a PSA-dispersion adhesive or acrylate copolymer microspheres.

8. The nutrient medium unit of claim 1 , wherein the fixing edge ( 21 ) defines a fixing surface that is concavely cambered towards two predetermined sides.

9. The nutrient medium unit of claim 1 wherein the lower part ( 15 , 15 ′) is dish-shaped and has a nutrient medium ( 17 , 17 ′) on whose top side ( 19 , 19 ′) facing the lid ( 16 ) the filter ( 4 , 4 ′) adhering to the lid ( 16 ) can be laid down.

10. The nutrient medium unit of claim 9 , wherein the top side ( 19 , 19 ′) of the nutrient medium ( 17 , 17 ′) is convexly cambered.

11. The nutrient medium unit of claim 9 , wherein the lower part ( 15 ′) has an outer wall, the support ring ( 18 ) that supports the nutrient medium ( 17 ′) laterally in the lower part ( 15 ′) has an inside diameter that corresponds approximately to the outside diameter of the filter ( 4 , 4 ′) and is arranged concentrically within the outer wall of the lower part ( 15 ′).

12. The nutrient medium unit of claim 11 , wherein the support ring ( 18 ) is positioned and designed such that by making contact or closure with the adhesive layer ( 27 ) of the lid ( 16 ) the support ring ( 18 ) reduces any possible variation in the adhesive properties during storage.

13. A nutrient unit medium comprising:
a filtration device ( 1 ) having a filter support ( 5 );
a filter supported removably on the filter support ( 5 ), the filter having an outer peripheral edge ( 13 , 13 ′) and being continuous at all positions inward of the outer peripheral edge ( 13 , 13 ′);
a lower part ( 15 , 15 ′) with a support ring and being filled with nutrient medium inward of the support ring; and
a lid ( 16 ) having a top wall, an outer wall projecting from the top wall and having an inside diameter that is greater than the outside diameter of the filter support of the filtration device ( 1 ) and greater than an outside diameter of the lower part ( 15 , 15 ′), the lid ( 16 ) further having an annular inner wall ( 23 ) projecting from the top wall at locations inward of the outer wall, and end of the annular inner wall ( 23 ) remote from the top wall defining a fixing edge ( 21 ) facing away from the top wall of the lid and connected to the outer peripheral edge ( 13 , 13 ′) of the filter ( 4 , 4 ′) via an adhesive bond ( 22 ) in order to remove the filter ( 4 ) from the filtration device ( 1 ) by telescoping the lid ( 16 ) over the filter support ( 5 ), the annular inner wall ( 23 ) of the lid ( 16 ) projecting the top wall thereof a sufficient distance such that areas of a surface of the filter inward of the annular inner wall ( 23 ) contact the nutrient medium when the lid ( 16 ) is telescoped over the lower part ( 15 , 15 ′).

14. The nutrient medium unit of claim 13 , wherein the inside diameter of the outer wall of the lid ( 16 ) is only slightly greater than the outside diameter of the filter support.

15. The nutrient medium unit of claim 1 , wherein the adhesive bond ( 22 ) between the fixing edge ( 21 ) and filter ( 4 ) is interrupted in places in order to ensure an exchange of air.

16. The nutrient medium unit of claim 15 , wherein the fixing edge ( 21 ) of the lid ( 16 ) is interrupted by at least one cutout in order to ensure an exchange of air.

17. The nutrient medium unit of claim 16 , wherein the fixing edge ( 21 ) of the lid ( 16 ) is reduced to at least two fixing pins ( 29 ) via which the filter ( 4 ) can be connected to the lid ( 16 ).

18. The nutrient medium unit of claim 1 , wherein the lid ( 16 ) has a recloseable gas-feed aperture in order to ensure an exchange of air.

19. The nutrient medium unit of claim 18 , wherein the nutrient medium ( 17 , 17 ′) is formed from agar.

20. The nutrient medium unit of claim 19 , characterized in that the filter ( 4 ) is designed as a membrane filter.

21. The nutrient medium unit of claim 1 wherein a lower part ( 3 ) of the device having a membrane filter comprises an attachment ( 2 ) or funnel ( 7 ) positioned over a base ( 6 ) or guides of the lower part ( 3 ) of the device such that an active filtration surface of the membrane filter Is positionable over the base ( 6 ) or the guides with an annular inner wall ( 23 ) of the lid ( 16 ) in a secure fashion outside the active filtration surface.

22. The nutrient medium unit of claim 21 wherein the lower part ( 3 ) is a disposable article and is made of plastic.

23. The nutrient medium unit of claim 21 wherein the filtration device ( 1 ) forms a disposable system with the lower part ( 3 ), the filter ( 4 ) and an attachment ( 2 ), and is made of plastic.

Assignees

• Pflanz Karl
• Sartorius Stedim Biotech Gmbh

Inventors

• Pflanz Karl

Classifications

• C12M23/10 Primary

  Petri dish (crystallising dishes B01L3/06) · CPC title

• G01N2001/4088

  filtration · CPC title

• B01L3/5635

  connecting two containers face to face, e.g. comprising a filter · CPC title

• B01L3/502

  with fluid transport, e.g. in multi-compartment structures · CPC title

• B01L2300/048

  enabling gas exchange, e.g. vents · CPC title