EP0053869A2
Expired / Lapsed
EP
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Method and apparatus for stirring particles in suspension such as microcarriers for anchorage-dependent living cells in a liquid culture medium
Assignee: Techne Cambridge Ltd
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Filing: 1981-05-06
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Granted: —
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Expires: 2001-05-06
Abstract
Abstract Stirring apparatus for stirring particles in a liquid medium comprising a cylindrical stirring vessel (1) having a stirring rod (2) extending within the vessel to stir its contents. The rod (2) has a bulbous tip (2A) which describes an orbital path in the vessel to sweep out an annular trough or channel (5) formed in the bottom of the vessel. The annular trough or channel (5) is contoured in section (6) to follow the flow lines set up in the medium by secondary motion stirring effects. In this way accumulation of particles due to the secondary motion, which would otherwise occur at the corners and centre of the bottom of the vessel, is avoided. The apparatus is advantageously useful in cell culture research particularly for stirring microcarriers in a liquid culture medium because it becomes possible to maintain the microcarriers in uniform suspension at lower stirring speeds than heretofore possible thus avoiding damage to the growing cells and improving overall cell yield.
Inventors
- 👤 George Frederick Cooke
- 👤 James Moffat Pearson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 00:32
CPC Classifications
C; C12; C12M; C12M23/00; C12M23/02; C12M23/08; B; B01; B01F; B01F27/00; B01F27/80; B01F27/95; B01F31/00; B01F31/42; B01F33/00; B01F33/45; B01F33/453; B01F33/4537; C12M25/00; C12M25/16; C12M27/00; C12M27/02; C12M27/18; C12M27/20; B01F27/23; B01F27/232; B01F27/2324
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
57 words
Apparatus for stirring particles in a liquid medium comprising a stirring vessel (1), an elongate stirrer (2) extending within the vessel (1) to stir its contents, characterised in that the vessel (1) is shaped (3,4,5,6) to deter the accumulation of particles at the bottom of the vessel caused by secondary motion stirring effects (S) within the vessel.
Claim 2
Dependent Claim
57 words
Apparatus for stirring particles in a liquid medium comprising a stirring vessel (1), an elongate stirrer (2) extending within the vessel (1) to stir its contents, characterised in that the vessel (1) is shaped (3,4,5,6) to deter the accumulation of particles at the bottom of the vessel caused by secondary motion stirring effects (S) within the vessel.
Claim 3
Dependent Claim
85 words
Apparatus as claimed in Claim 1 wherein to provide said shaping the bottom of the vessel has a substantially centrally located conical portion (3) forming an annular trough or channel (5) therein, said stirrer (2) extending within the vessel such that the end of the stirrer is movable to sweep said trough or channel, which is contoured in section.(6) to or substantially to the flow lines at the bottom of the vessel (1) set up by secondary motion stirring effects (S) with the vessel (1).
Claim 4
Dependent Claim
87 words
Apparatus as claimed in Claim 1 or 2 wherein the vessel is cylindrical, said trough or channel (5) being contoured to said flow lines by being radiused, at the least, at its corners respectively between the inner wall of the vessel (1) and between the interior surface of the conical portion (3) and the bottom of the vessel (1), and at the most, the whole extent of its interior surface between the inner wall of the vessel (1) and the apex (4) of said conical portion (3).
Claim 5
Dependent Claim
51 words
Apparatus as claimed in Claim 3 wherein the radiused dimensions of the trough or channel (5) are within the range 1/4 to 1/10 the diameter (D) of the vessel (1), the height of the conical portion (3) being within the range 1/3 to 1/6 the diameter (D) of the vessel (1).
Claim 6
Dependent Claim
49 words
Apparatus as claimed in Claim 4 wherein the conical portion (3) has a rounded apex (4) its axis lying on the axis (7) of the vessel, and the base diameter of said conical portion (3) is within the range 1/1.5 to 1/5 the diameter (D) of the vessel (1).
Claim 7
Dependent Claim
29 words
Apparatus as claimed in any preceding claim wherein said elongate stirrer (2) has a bulbous tip (2A) at said end thereof which sweeps said annular trough or channel (5).
Claim 8
Dependent Claim
28 words
Apparatus as claimed in Claim 6 wherein the dimensions of said bulbous tip (2A) are within the range 1/2 to 1/20 the diameter (D) of the vessel (1).
Claim 9
Dependent Claim
84 words
Apparatus for stirring the contents of a vessel as claimed in Claim ? further including means (10, 12, 13, 14, 23, 30) for supporting the stirrer (2) within the vessel (1), magnetic means (16, 19) for moving said end of the stirrer (2) in an orbital path around the bottom of the vessel, said supporting means (10, 12, 13, 14, 23, 30) being capable of allowing said end to move in said orbital path while the stirrer (2) remains irrotational around its own axis.
Claim 10
Dependent Claim
83 words
Apparatus as claimed in Claim 8 wherein said supporting means comprises a mounting member (12) which sits on the rim of an open neck of said vessel (1), said mounting member (12) having a projection (13, 21, 32) depending internally of the vessel (1), a flexible link (14, 23, 30) between the projection (13, 12, 32) and the other end of said stirrer (2), and a closure cap (10) for said open neck retaining said mounting member (12) in position on said rim.
Claim 11
Dependent Claim
85 words
Apparatus as claimed in Claims 8 or 9,wherein said magnetic means comprises a'first magnet (16) in said end of the stirrer (2), a second magnet (19) positioned exteriorly of the vessel (1) to attract the first magnet (16) and cause the axis of the stirrer to lie at an angle to the axis (7)-of the vessel (1), and means (19, 18) for rotating the second magnet such that under the mutual attraction between the first and second magnets said end rotates in said orbital path.
Claim 12
Dependent Claim
67 words
Apparatus as claimed in Claim 10 wherein said second magnet (19) is mounted on a disc (17) by means of a screw (20), the screw (20) being positioned on the disc (17) offset with respect to the centre of the disc, whereby to allow rotatable adjustment of said second magnet (19) on the disc and thus the diameter of orbit of said end of the stirrer (2).
Claim 13
Dependent Claim
30 words
Apparatus as claimed in Claim 11 wherein the central axis of the vessel (7) passes through the axis of said depending projection (14) and the centre of the disc (19).
Claim 14
Independent Claim
38 words
A method of stirring particles in a liquid medium compring stirring the particles in a stirring vessel shaped to deter the accumulation of particles at the bottom of the vessel by secondary motion stirring effects within the vessel.
Claim 15
Independent Claim
38 words
A method of stirring particles in a liquid medium compring stirring the particles in a stirring vessel shaped to deter the accumulation of particles at the bottom of the vessel by secondary motion stirring effects within the vessel.
Claim 16
Dependent Claim
83 words
A method as claimed in Claim 13 wherein the shaping is provided by a substantially centrally located conical portion forming an annular trough or channel in the bottom of the vessel, the trough or channel being contoured to or substantially to the flow lines set up in the vessel by the effects.of secondary stirring motion, the end of the stirrer'being moved within the vessel in an orbital path to sweep out said annular trough or channel to maintain the particles in uniform suspension.
Claim 17
Dependent Claim
22 words
A method as claimed in Claim 14 wherein the end of the stirrer sweeping out the annular trough or channel is bulbous.
Claim 18
Independent Claim
29 words
A method as claimed in Claims 13, 14 or 15 wherein the stirrer is moved within the vessel at a speed within the range 5 rpm to 80 rpm.
Claim 19
Dependent Claim
37 words
A method as claimed in Claim 15 wherein the end of the stirrer is moved in said orbital path by magnetic attraction between an externally moving magnet and a magnet embedded in said end of the stirrer.
Claim 20
Independent Claim
24 words
A method as claimed in any one of Claims 13 to 17 wherein the particles are microcarriers being stirred in a liquid culture medium.
Claim 21
Dependent Claim
13 words
A method as claimed in Claim 18 wherein the microcarriers are stirred intermittently.
Claim 22
Independent Claim
42 words
A method as claimed in Claims 18 or 19 wherein the stirrer is accelerated slowly from rest to achieve a desired steady state stirring speed, and then decelerated slowly to zero after a predetermined time of stirring at said steady state speed.
References Cited (Backward Citations)
No citation records indexed.
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