US4734192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiwell membrane filtration apparatus
Assignee: EMD Millipore Corp
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Filing: 1985-06-21
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Granted: 1988-03-29
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Expires: 2005-06-21
Abstract
Abstract A multiwell filtration apparatus for the assay of microliter quantities is provided which prevents fluid loss by capillary action and gravity flow through a microporous membrane or ultrafilter. The filtration apparatus is particularly advantageous in assays requiring maintenance of fluid within the reaction wells for substantial time periods and in small sample volume assays in the range of 100 microliter volumes.
Inventors
- 👤 Helena M. Champion
- 👤 Joseph J. Pierog
- 👤 Joseph E. Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:08
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/14; B01D61/18; B01L; B01L3/00; B01L3/50; B01L3/502; B01L3/5025; B01L3/50255; G; G01; G01N; G01N33/00; G01N33/48
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
206 words
A filtration apparatus able to retain liquid for extended periods of time comprising: a plate having a thickness and a plurality of apertures extending through the thickness of the plate; filtration means comprising a member selected from the group consisting of a microporous membrane and an ultrafiltration membrane disposed over one end of each of said apertures such that a plurality of wells each having a discrete filtering area are formed; a hydrophobic fabric attached to said filtration means adjacent to said filtering areas and spaced apart from said filtering areas, said filtering areas and hydrophobic fabric defining spaces where liquid can be retained, said hydrophobic fabric positioned to prevent liquid placed in said wells from passing through said filtration means and said hydrophobic fabric by capillary action and gravity flow; operably connected means for applying a differential pressure across said filtering areas and said hydrophobic fabric for effecting passage of said liquid sequentially through a said filtering area, said filtration means, a said space and said hydrophobic fabric; a second plate defining a plurality of chambers, only one chamber being associated with each of said apertures, and operably connected means for providing that only one said chamber receives all liquid passing through the associated aperture.
Claim 2
Dependent Claim
206 words
A filtration apparatus able to retain liquid for extended periods of time comprising: a plate having a thickness and a plurality of apertures extending through the thickness of the plate; filtration means comprising a member selected from the group consisting of a microporous membrane and an ultrafiltration membrane disposed over one end of each of said apertures such that a plurality of wells each having a discrete filtering area are formed; a hydrophobic fabric attached to said filtration means adjacent to said filtering areas and spaced apart from said filtering areas, said filtering areas and hydrophobic fabric defining spaces where liquid can be retained, said hydrophobic fabric positioned to prevent liquid placed in said wells from passing through said filtration means and said hydrophobic fabric by capillary action and gravity flow; operably connected means for applying a differential pressure across said filtering areas and said hydrophobic fabric for effecting passage of said liquid sequentially through a said filtering area, said filtration means, a said space and said hydrophobic fabric; a second plate defining a plurality of chambers, only one chamber being associated with each of said apertures, and operably connected means for providing that only one said chamber receives all liquid passing through the associated aperture.
Claim 3
Dependent Claim
244 words
A filtration apparatus able to retain liquid for extended periods of time comprising: a plate having a thickness and a plurality of apertures extending through the thickness of the plate; filtration means comprising a membrane selected from the group consisting of a microporous membrane and an ultrafiltration membrane disposed over one end of each of said apertures such that a plurality of wells each having a discrete filtering area are formed; a hydrophobic fabric attached to said filtration means adjacent to said filtering areas and spaced apart from said filtering areas, said filtering areas and hydrophobic fabric defining spaces where liquid can be retained, said hydrophobic fabric positioned to prevent liquid placed in said wells from passing through said filtration means and said hydrophobic fabric by capillary action and gravity flow; a second plate defining a plurality of chambers, only one chamber being associated with each of said apertures; operably connected means for applying a differential pressure across said filtering areas and said hydrophobic fabric for effecting passage of said liquid sequentially through a said filtering area, said filtration means, a said space and said hydrophobic fabric and into a chamber; and operably connected means for providing that only one said chamber receives all liquid passing through the associated aperture including a plurality of projections each aligned with an aperture and positioned beneath said filtration means to direct liquid passing through said filtration means and said hydrophobic fabric to only one of said chambers.
Claim 4
Dependent Claim
244 words
A filtration apparatus able to retain liquid for extended periods of time comprising: a plate having a thickness and a plurality of apertures extending through the thickness of the plate; filtration means comprising a membrane selected from the group consisting of a microporous membrane and an ultrafiltration membrane disposed over one end of each of said apertures such that a plurality of wells each having a discrete filtering area are formed; a hydrophobic fabric attached to said filtration means adjacent to said filtering areas and spaced apart from said filtering areas, said filtering areas and hydrophobic fabric defining spaces where liquid can be retained, said hydrophobic fabric positioned to prevent liquid placed in said wells from passing through said filtration means and said hydrophobic fabric by capillary action and gravity flow; a second plate defining a plurality of chambers, only one chamber being associated with each of said apertures; operably connected means for applying a differential pressure across said filtering areas and said hydrophobic fabric for effecting passage of said liquid sequentially through a said filtering area, said filtration means, a said space and said hydrophobic fabric and into a chamber; and operably connected means for providing that only one said chamber receives all liquid passing through the associated aperture including a plurality of projections each aligned with an aperture and positioned beneath said filtration means to direct liquid passing through said filtration means and said hydrophobic fabric to only one of said chambers.
Claim 5
Dependent Claim
18 words
The filtration apparatus as recited in claim 1 or 2 wherein said filtration means includes a microporous membrane.
Claim 6
Dependent Claim
27 words
The filtration apparatus as recited in claim 1 or 2 wherein said filtration means includes a microporous membrane having a pore size of at least 25 nanometers.
Claim 7
Dependent Claim
38 words
The filtration apparatus as recited in claims 1 or 2 wherein said filtration means is an ultrafiltration membrane havine a pore size which effects retention of molecules ranging in molecular weight from one hundred to two million daltons.
Claim 8
Dependent Claim
25 words
The filtration apparatus as recited in claim 1 or 2 wherein said hydrophobic fabric is selected from the group consisting of woven or nonwoven polymers.
Claim 9
Dependent Claim
25 words
The filtration apparatus as recited in claim 1 or 2 wherein said hydrophobic fabric is selected from the group consisting of polyesters, polyolefins and polytetrafluoroethylene.
Claim 10
Dependent Claim
17 words
The filtration apparatus as recited in claim 1 or 2 wherein said hydrophobic fabric is heat bondable.
Claim 11
Dependent Claim
18 words
The filtration apparatus as recited in claim 1 or 2 wherein said hydrophobic fabric is attached with adhesive.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |