CA1066674A - Mouth filter for use with pipettes - Google Patents
Mouth filter for use with pipettesInfo
- Publication number
- CA1066674A CA1066674A CA293,200A CA293200A CA1066674A CA 1066674 A CA1066674 A CA 1066674A CA 293200 A CA293200 A CA 293200A CA 1066674 A CA1066674 A CA 1066674A
- Authority
- CA
- Canada
- Prior art keywords
- filter membrane
- pipette
- housing
- mouth
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012528 membrane Substances 0.000 claims abstract description 38
- 239000007788 liquid Substances 0.000 claims abstract description 29
- 241000894006 Bacteria Species 0.000 claims abstract description 15
- 239000011347 resin Substances 0.000 claims abstract description 9
- 229920005989 resin Polymers 0.000 claims abstract description 9
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 6
- 239000011148 porous material Substances 0.000 claims description 4
- 230000003405 preventing effect Effects 0.000 claims description 2
- 230000037431 insertion Effects 0.000 claims 1
- 238000003780 insertion Methods 0.000 claims 1
- 230000004888 barrier function Effects 0.000 abstract description 3
- 210000004379 membrane Anatomy 0.000 description 5
- 230000037406 food intake Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 239000012472 biological sample Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/0002—Casings; Housings; Frame constructions
- B01D46/0012—In-line filters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/0031—Degasification of liquids by filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/54—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms
- B01D46/543—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms using membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
- B01L3/0213—Accessories for glass pipettes; Gun-type pipettes, e.g. safety devices, pumps
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
- A61M5/165—Filtering accessories, e.g. blood filters, filters for infusion liquids
- A61M2005/1657—Filter with membrane, e.g. membrane, flat sheet type infusion filter
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/36—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests with means for eliminating or preventing injection or infusion of air into body
- A61M5/38—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests with means for eliminating or preventing injection or infusion of air into body using hydrophilic or hydrophobic filters
- A61M5/385—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests with means for eliminating or preventing injection or infusion of air into body using hydrophilic or hydrophobic filters using hydrophobic filters
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Clinical Laboratory Science (AREA)
- Devices For Use In Laboratory Experiments (AREA)
- Sampling And Sample Adjustment (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In accordance with the invention there is provided a mouth filter for use with pipettes to insure that none of the liquid or any of the bacteria in the liquid being drawn into the pipette reach the mouth of the technician applying the suction. The filter comprises an organic resin housing having a filter membrane therein which divides the housing into an inlet chamber and an exit chamber, the filter membrane being hydrophobic and constituting a bacteria barrier. The housing has tubular extensions extending from the oppositely disposed axial end walls thereof. A tube is secured to one exten-sion of the housing and is adapted to be secured in communicating relationship with a pipette into which the liquid is to be drawn. Connected to the other housing extension is a mouthpiece for mouth-applied suction by the technician, which suction is communicated through the filter membrane and tube to the pipette.
In accordance with the invention there is provided a mouth filter for use with pipettes to insure that none of the liquid or any of the bacteria in the liquid being drawn into the pipette reach the mouth of the technician applying the suction. The filter comprises an organic resin housing having a filter membrane therein which divides the housing into an inlet chamber and an exit chamber, the filter membrane being hydrophobic and constituting a bacteria barrier. The housing has tubular extensions extending from the oppositely disposed axial end walls thereof. A tube is secured to one exten-sion of the housing and is adapted to be secured in communicating relationship with a pipette into which the liquid is to be drawn. Connected to the other housing extension is a mouthpiece for mouth-applied suction by the technician, which suction is communicated through the filter membrane and tube to the pipette.
Description
1066674 :
. The subject matter of the present invention is a mouth filter device for use with pipettes which in use require mouth-applied suction to draw a -;
liquid into the pipette.
Chemists, biologists, and others skilled in the art readily appre-ciate the hazard involved in the careless use of a pipette. That is, if while -~
using a pipette the technician!s attention is distracted from the task at ~ -hand--that of drawing liquid into the pipette by the application of mouth-applied suction--it is easily possible for the technician to end up with a mouthful of the liquid being drawn. Many have been the chemistry students and chemists who have had to spit out some acid or other harmful chemical as the result of the use of a pipette without close attention. In the areas of biology, microbiology, and the medical profession, there is the still further hazard, in the use of a pipette, of the ingestion of harmful bacteria present in the liquid being drawn into the pipette. Protection for the technician is here required, not just against the careless use of the pipette but even when the technician uses the pipette with utmost care. That is, the biologist or metical technician might, on occasion, be sucking into the pipette a liquid pregnant with harmful bacteria which, absent protection, could reach the mouth, by way of the vapor above the liquid, albeit the pipette would be carefully -.
uset such that the liquid itself did not reach the mouth.
The present invention provides a practical, low-cost device for ; protecting the chemist, biologist, medical technician or other person using a pipette or the like from the aforesaid hazards.
According to the present invention there is provided a mouth filter device for use with pipettes where suction is applied by the mouth to draw liquid into the pipette, said device comprising a flat, cylindrical, organic resin housing, a round filter membrane in and extending transverse to the axis of said housing and in sealed relationship with said housing so as to divide sait housing into an inlet chamber on one side of said filter membrane and an exit chamber on the other side of said filter membrane, said filter membrane -(~ . .
~ 1066674 : .
being hydrophobic thereby to allow the passage of gas therethrough while pre-venting the passage of liquid therethrough and said filter membrane having a submicron pore size sufficiently small to prevent the passage of bacteria therethrough, a tubular extension on and integral with one axial end of said .
housing extending axially from and communicating with said inlet chamber, a tubular extension on and integral with the other axial end of said housing extending axially from and communicating with said exit chamber, an elastomer-ic tube having one end thereof connected and communicating with said first mentioned extension, the other end of said tube being adapted to be fitted in 10 sealed relationship to the pipette, and an organic resin mouthpiece connected to said second mentioned tubular extension and having an opening therethrough communicating with said exit chamber whereby mouth-applied suction to said mouthpiece creates suction through the filter membrane and said tube to draw -liquid into the pipette to which the tube is fitted thereby to draw liquid thereinto, said ~ilter membrane assuring against any of the liquid or any bacteria therein reaching the mouth.
The invention will now be described in detail, in part .'' ~ .
`
.
,.
.~
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1~366674 by reference to the accompanying drawings in which:
FIGURE 1 is a perspective view of a mouth filter : .
device made in accordance with the invention;
FIGURE 2 is a side view in cross-section, and in some-what enlarged scale, of a portion of the device shown in FIGUREl; and FIGURE 3 is a perspective view of another embodiment of the ~nvention.
Referring now to FIGURES 1 and 2, the mouth filter de-vice of the present invention comprises a flat, cylindrical,rigid, transparent organic resin housing 2, there being a round filter membrane 4 extending transverse to the axis of the housing and in sealed relationship with the cylindrical side wall of the ; housing. Hence, the filter membrane divides the housing into an inlet chamber 6 on one side of the filter membrane and an exit chamber 8 on the other side of the filter membrane. For ample support of the filter membrane, which may be of relatively delicate construction, the housing can be provided with circum-ferentially spaced, radially extending upper and lower ribs, 10 and 12 respectively, which contact the membrane and provide the desired physical support. The housing can be constructed of ; upper and lower transparent organic resin moldings which are snapped together with the membrane therebetween, as shown, after , which the molding can be heat sealed together around the circum-s` 25 ference thereof so as to provide a hermetic seal.
; The filter membrane 4 must be hydrophobic, i.e. it must be such that it enables the passage therethrough of gas but à prevents the passage therethrough of liquid. Still further, the ; filter membrane must constitute a bacteria barrier, which means 30 that the filter membrane must have a submicron pore siz~- suffi-
. The subject matter of the present invention is a mouth filter device for use with pipettes which in use require mouth-applied suction to draw a -;
liquid into the pipette.
Chemists, biologists, and others skilled in the art readily appre-ciate the hazard involved in the careless use of a pipette. That is, if while -~
using a pipette the technician!s attention is distracted from the task at ~ -hand--that of drawing liquid into the pipette by the application of mouth-applied suction--it is easily possible for the technician to end up with a mouthful of the liquid being drawn. Many have been the chemistry students and chemists who have had to spit out some acid or other harmful chemical as the result of the use of a pipette without close attention. In the areas of biology, microbiology, and the medical profession, there is the still further hazard, in the use of a pipette, of the ingestion of harmful bacteria present in the liquid being drawn into the pipette. Protection for the technician is here required, not just against the careless use of the pipette but even when the technician uses the pipette with utmost care. That is, the biologist or metical technician might, on occasion, be sucking into the pipette a liquid pregnant with harmful bacteria which, absent protection, could reach the mouth, by way of the vapor above the liquid, albeit the pipette would be carefully -.
uset such that the liquid itself did not reach the mouth.
The present invention provides a practical, low-cost device for ; protecting the chemist, biologist, medical technician or other person using a pipette or the like from the aforesaid hazards.
According to the present invention there is provided a mouth filter device for use with pipettes where suction is applied by the mouth to draw liquid into the pipette, said device comprising a flat, cylindrical, organic resin housing, a round filter membrane in and extending transverse to the axis of said housing and in sealed relationship with said housing so as to divide sait housing into an inlet chamber on one side of said filter membrane and an exit chamber on the other side of said filter membrane, said filter membrane -(~ . .
~ 1066674 : .
being hydrophobic thereby to allow the passage of gas therethrough while pre-venting the passage of liquid therethrough and said filter membrane having a submicron pore size sufficiently small to prevent the passage of bacteria therethrough, a tubular extension on and integral with one axial end of said .
housing extending axially from and communicating with said inlet chamber, a tubular extension on and integral with the other axial end of said housing extending axially from and communicating with said exit chamber, an elastomer-ic tube having one end thereof connected and communicating with said first mentioned extension, the other end of said tube being adapted to be fitted in 10 sealed relationship to the pipette, and an organic resin mouthpiece connected to said second mentioned tubular extension and having an opening therethrough communicating with said exit chamber whereby mouth-applied suction to said mouthpiece creates suction through the filter membrane and said tube to draw -liquid into the pipette to which the tube is fitted thereby to draw liquid thereinto, said ~ilter membrane assuring against any of the liquid or any bacteria therein reaching the mouth.
The invention will now be described in detail, in part .'' ~ .
`
.
,.
.~
- la -, ~^~
1~366674 by reference to the accompanying drawings in which:
FIGURE 1 is a perspective view of a mouth filter : .
device made in accordance with the invention;
FIGURE 2 is a side view in cross-section, and in some-what enlarged scale, of a portion of the device shown in FIGUREl; and FIGURE 3 is a perspective view of another embodiment of the ~nvention.
Referring now to FIGURES 1 and 2, the mouth filter de-vice of the present invention comprises a flat, cylindrical,rigid, transparent organic resin housing 2, there being a round filter membrane 4 extending transverse to the axis of the housing and in sealed relationship with the cylindrical side wall of the ; housing. Hence, the filter membrane divides the housing into an inlet chamber 6 on one side of the filter membrane and an exit chamber 8 on the other side of the filter membrane. For ample support of the filter membrane, which may be of relatively delicate construction, the housing can be provided with circum-ferentially spaced, radially extending upper and lower ribs, 10 and 12 respectively, which contact the membrane and provide the desired physical support. The housing can be constructed of ; upper and lower transparent organic resin moldings which are snapped together with the membrane therebetween, as shown, after , which the molding can be heat sealed together around the circum-s` 25 ference thereof so as to provide a hermetic seal.
; The filter membrane 4 must be hydrophobic, i.e. it must be such that it enables the passage therethrough of gas but à prevents the passage therethrough of liquid. Still further, the ; filter membrane must constitute a bacteria barrier, which means 30 that the filter membrane must have a submicron pore siz~- suffi-
-2-. .
~066674 ciently small to block the migration of bacteria from one side to the other thereof. Such hydrophobic bacteria-barrier mem-branes are already known in the art and are commercially avail-able, as exemplified by the filter membrane marketed by the assignee of the present invention under the trademark UAcropor'', - such membrane having a pore size of from about .2 to .5 microns.
Such a filter membrane consists of a unitary organic resin film, typically .005 inches in thickness, having random and irregular passages therethrough of sufficiently small dimensions to block the passage of anything, including bacteria, having a size greater than the aforesaid .5 microns.
Extending axially from and integral with one axial end of the housing and communicating with the inlet chamber 6 is a tubular extension 14. Extending axially from and integral with the opposite axial end wall of the housing is a tubular exten-sion 16 which communicates with the exit chamber 8.
Connected to and communicating with the tubular exten-sion 14 is a flexible elastomeric tube 18. The end 20 of the elastomeric tube 18 is, in its unstretched condition, of some-, 20 what lesser internal diameter than the external diameter of the lower end of the housing extension 14 and is sealingly secured thereto simply by way of its inherent resiliency which provides ,, an excellent mechanical and leak-free connection. The opposite end 22 of the flexible tube is adapted to be fitted in sealed relationship to the upper end 24 of a pipette into which it is desired to draw the liquid. The connection between the end 22 of the flexible tube and the upper end 24 of the pipette is similar to the connection between the end 20 of the flexible tube and the tubular projection 14 of the filter membrane hous-ing. That is, the normal unstretched internal diameter of the ' ~ -3-' ~-.
. - , ~066674 flexible tube is somewhat less than the external diameter of the upper end of the pipette, and the attachment of the end of the flexible tube to the pipette is accomplished by a stretching of the end of the elastomeric tube thereby providing a good mechan-ical and leak proof, though rapidly detachable, connection.
Connected to the tubular extension 16 is a molded organic resin mouthpiece 26. The mouthpiece has an opening 28 therethrough which communicates with the passage through the extension 16 and hence communicates with the exit chamber of the filter membrane housing. In the embodiment shown in FIGURES 1 and 2, there is a friction fit between the tapered outer surface of the lower end 30 of the mouthpiece and the tapered interior surface of the extension 16, the friction fit being ample to maintain the mouthpiece secured to the extension in sealed relationship therewith.
It is preferred that the flexible tube be at least about 12 inches long so that when the flexible tube is connected to the pipette, the technician who, with his mouth draws the ' vacuum through the mouthpiece, can be this distance away, later-20 ally, from the pipette so as to be able to clearly view the liquid level attained in the pipette as the mouth suction is ` applied. On the other hand, a tube length of greater than 24 A ~
inches is cumbersome and serves no useful purpose.
In operation, the chemist, biologist, or other tech-nician connects the end of the flexible tube to the pipette and then, with the pipette inserted into the liquid desired to be drawn, applies mouth suction to the mouthpiece 26 until the desired level of the liquid in the pipette is attained. But in the event the technician's attention should be distracted, the filter membrane 4 absolutely insures against the liquid being :
.
~0666'74 drawn into the technicianls mouth since the filter membrane 4 is hydrophobic and hence blocks the passage of any liquid--though allowing the passage of gas therethrough. As regards use by bIologists where the liquid being drawn into the pipette might contain virulent bacteria, the filter membrane of the device, being a bacteria barrier, fully protects the technician against the ingestion of the bacteria even though such bacteria might be present in the vapor phase above the liquid. Hence, the device of the present invention provides a low-cost, convenient way to protect technical personnel who are required, by mouth-applied suction, to withdraw liquid chemical or biological samples into pipettes.
The FIGURE 3 embodiment differs from that of FIGURES
1 and 2 chiefly in that when in use, the filter membrane is located more closely adjacent the pipette. Referring to FIGURE
; 3, the filter housing 30, the filter membrane (not shown) there-in and the inlet and outlet tubular extensions, 32 and 34 respec-tively, of the housing are all identical in structure to the like components shown in the FIGURE 1-2 embodiment; however, in the FIGURE 3 embodiment the mouthpiece 36 is connected to the outlet tubular extension 34 of the filter housing by a flexible elastomeric tube 38 which can be the same as, but preferably shorter than, the flexible elastomeric tube 18 of the FIGURE 1-2 embodiment. Connected to the inlet tubular extension 32 of the filter housing is an elastomeric tube 40 which is of generally conical external shape. The tube can be relatively short--about 3/4" to 1", for example. When the FIGURE 3 embodiment is used, the conical elastomeric tube 40 is inserted into the upper end of the pipette until a good seal is accompl~shed between the pipette and the elastomeric tube which is relatively soft and .. _ .. ..
. `; ` ` ~ ' lOG6674 hence enables a good s-eal, Because of the conical shape of the elastomeric tube 40, th.e filter can be used with any of a vari-ety of different sized pipettes having different diameters, the elastomeric tube extending only a short distance into a pipette of small diameter and extending further into a pipette of larger diameter. In FIGURE 3, 42 is the upper end of a pipette into which the conical tube 40 has been inserted.
It will be understood that whereas the invention has been described in its particulars with reference to preferred . 10 embodiments thereof, various changes and modifications may be :. made all within the full and intended scope of the claims which follow. .
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''~ ' '. '~ ' ' ' ' '' "' ' , '.' ' ' ': ' ' : ' : . " .
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~066674 ciently small to block the migration of bacteria from one side to the other thereof. Such hydrophobic bacteria-barrier mem-branes are already known in the art and are commercially avail-able, as exemplified by the filter membrane marketed by the assignee of the present invention under the trademark UAcropor'', - such membrane having a pore size of from about .2 to .5 microns.
Such a filter membrane consists of a unitary organic resin film, typically .005 inches in thickness, having random and irregular passages therethrough of sufficiently small dimensions to block the passage of anything, including bacteria, having a size greater than the aforesaid .5 microns.
Extending axially from and integral with one axial end of the housing and communicating with the inlet chamber 6 is a tubular extension 14. Extending axially from and integral with the opposite axial end wall of the housing is a tubular exten-sion 16 which communicates with the exit chamber 8.
Connected to and communicating with the tubular exten-sion 14 is a flexible elastomeric tube 18. The end 20 of the elastomeric tube 18 is, in its unstretched condition, of some-, 20 what lesser internal diameter than the external diameter of the lower end of the housing extension 14 and is sealingly secured thereto simply by way of its inherent resiliency which provides ,, an excellent mechanical and leak-free connection. The opposite end 22 of the flexible tube is adapted to be fitted in sealed relationship to the upper end 24 of a pipette into which it is desired to draw the liquid. The connection between the end 22 of the flexible tube and the upper end 24 of the pipette is similar to the connection between the end 20 of the flexible tube and the tubular projection 14 of the filter membrane hous-ing. That is, the normal unstretched internal diameter of the ' ~ -3-' ~-.
. - , ~066674 flexible tube is somewhat less than the external diameter of the upper end of the pipette, and the attachment of the end of the flexible tube to the pipette is accomplished by a stretching of the end of the elastomeric tube thereby providing a good mechan-ical and leak proof, though rapidly detachable, connection.
Connected to the tubular extension 16 is a molded organic resin mouthpiece 26. The mouthpiece has an opening 28 therethrough which communicates with the passage through the extension 16 and hence communicates with the exit chamber of the filter membrane housing. In the embodiment shown in FIGURES 1 and 2, there is a friction fit between the tapered outer surface of the lower end 30 of the mouthpiece and the tapered interior surface of the extension 16, the friction fit being ample to maintain the mouthpiece secured to the extension in sealed relationship therewith.
It is preferred that the flexible tube be at least about 12 inches long so that when the flexible tube is connected to the pipette, the technician who, with his mouth draws the ' vacuum through the mouthpiece, can be this distance away, later-20 ally, from the pipette so as to be able to clearly view the liquid level attained in the pipette as the mouth suction is ` applied. On the other hand, a tube length of greater than 24 A ~
inches is cumbersome and serves no useful purpose.
In operation, the chemist, biologist, or other tech-nician connects the end of the flexible tube to the pipette and then, with the pipette inserted into the liquid desired to be drawn, applies mouth suction to the mouthpiece 26 until the desired level of the liquid in the pipette is attained. But in the event the technician's attention should be distracted, the filter membrane 4 absolutely insures against the liquid being :
.
~0666'74 drawn into the technicianls mouth since the filter membrane 4 is hydrophobic and hence blocks the passage of any liquid--though allowing the passage of gas therethrough. As regards use by bIologists where the liquid being drawn into the pipette might contain virulent bacteria, the filter membrane of the device, being a bacteria barrier, fully protects the technician against the ingestion of the bacteria even though such bacteria might be present in the vapor phase above the liquid. Hence, the device of the present invention provides a low-cost, convenient way to protect technical personnel who are required, by mouth-applied suction, to withdraw liquid chemical or biological samples into pipettes.
The FIGURE 3 embodiment differs from that of FIGURES
1 and 2 chiefly in that when in use, the filter membrane is located more closely adjacent the pipette. Referring to FIGURE
; 3, the filter housing 30, the filter membrane (not shown) there-in and the inlet and outlet tubular extensions, 32 and 34 respec-tively, of the housing are all identical in structure to the like components shown in the FIGURE 1-2 embodiment; however, in the FIGURE 3 embodiment the mouthpiece 36 is connected to the outlet tubular extension 34 of the filter housing by a flexible elastomeric tube 38 which can be the same as, but preferably shorter than, the flexible elastomeric tube 18 of the FIGURE 1-2 embodiment. Connected to the inlet tubular extension 32 of the filter housing is an elastomeric tube 40 which is of generally conical external shape. The tube can be relatively short--about 3/4" to 1", for example. When the FIGURE 3 embodiment is used, the conical elastomeric tube 40 is inserted into the upper end of the pipette until a good seal is accompl~shed between the pipette and the elastomeric tube which is relatively soft and .. _ .. ..
. `; ` ` ~ ' lOG6674 hence enables a good s-eal, Because of the conical shape of the elastomeric tube 40, th.e filter can be used with any of a vari-ety of different sized pipettes having different diameters, the elastomeric tube extending only a short distance into a pipette of small diameter and extending further into a pipette of larger diameter. In FIGURE 3, 42 is the upper end of a pipette into which the conical tube 40 has been inserted.
It will be understood that whereas the invention has been described in its particulars with reference to preferred . 10 embodiments thereof, various changes and modifications may be :. made all within the full and intended scope of the claims which follow. .
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'~. , ' ', ' ' ' , ' ' ' ~
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. ', ' ' " . " , ' , , '.' ' . ' '
Claims (3)
1. A mouth filter device for use with pipettes where suction is applied by the mouth to draw liquid into the pipette, said device comprising a flat, cylindrical, organic resin hous-ing, a round filter membrane in and extending transverse to the axis of said housing and in sealed relationship with said hous-ing so as to divide said housing into an inlet chamber on one side of said filter membrane and an exit chamber on the other side of said filter membrane, said filter membrane being hydro-phobic thereby to allow the passage of gas therethrough while preventing the passage of liquid therethrough and said filter membrane having a submicron pore size sufficiently small to prevent the passage of bacteria therethrough, a tubular exten-sion on and integral with one axial end of said housing extend-ing axially from and communicating with said inlet chamber, a tubular extension on and integral with the other axial end of said housing extending axially from and communicating with said exit chamber, an elastomeric tube having one end thereof con-nected and communicating with said first mentioned extension, the other end of said tube being adapted to be fitted in sealed relationship to the pipette, and an organic resin mouthpiece connected to said second mentioned tubular extension and having an opening therethrough communicating with said exit chamber whereby mouth-applied suction to said mouthpiece creates suction through the filter membrane and said tube to draw liquid into the pipette to which the tube is fitted thereby to draw liquid thereinto, said filter membrane assuring against any of the liquid or any bacteria therein reaching the mouth.
2. A device as set forth in Claim 1 wherein said mouthpiece is connected directly to said second mentioned exten-sion.
3. A device as set forth in Claim 1 wherein said elastomeric tube has a conical shaped outer surface for insertion into a pipette in sealed relationship therewith and wherein said mouthpiece is connected to said second mentioned extension by a flexible tube.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US76845077A | 1977-02-14 | 1977-02-14 | |
| US05/840,685 US4111807A (en) | 1977-02-14 | 1977-10-11 | Mouth filter for use with pipettes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1066674A true CA1066674A (en) | 1979-11-20 |
Family
ID=27118055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA293,200A Expired CA1066674A (en) | 1977-02-14 | 1977-12-16 | Mouth filter for use with pipettes |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS53100889A (en) |
| CA (1) | CA1066674A (en) |
| DE (1) | DE7804147U1 (en) |
| FR (1) | FR2380059A1 (en) |
| GB (1) | GB1595742A (en) |
| IT (1) | IT1103874B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3316043A1 (en) * | 1983-05-03 | 1984-11-08 | Sartorius GmbH, 3400 Göttingen | SMALL FILTER FOR GAS FILTRATION |
| GB2157190B (en) * | 1984-03-13 | 1987-10-21 | Gore & Ass | Gas venting device |
| NZ216749A (en) * | 1985-09-06 | 1987-11-27 | Allied Corp | Snap assembled plastics bodied air filter |
| DE3635598A1 (en) * | 1986-10-20 | 1988-05-05 | Eppendorf Geraetebau Netheler | PIPETTING DEVICE WITH A CLIP-ON CONE FOR A PIPETTE TIP AND PIPETTE TIP FOR SUCH A PIPETTING DEVICE |
| US4892710A (en) * | 1987-07-07 | 1990-01-09 | Bioprobe International, Inc. | Cartridge assembly with multi-purpose closure tubing |
| US4941897A (en) * | 1987-11-05 | 1990-07-17 | L & H Technologies, Inc. | Microporous filter and method |
| DE4141823C2 (en) * | 1991-12-18 | 1994-12-15 | Mann & Hummel Filter | Liquid filter |
| DE102005005437A1 (en) * | 2005-02-05 | 2006-08-10 | Eppendorf Ag | Filter pipette tip |
| GB2568958A (en) * | 2017-12-04 | 2019-06-05 | Short Brothers Plc | Resin barrier device |
| CN113058672B (en) * | 2021-04-15 | 2022-09-02 | 四川大学华西医院 | Detachable pipettor with filtering device and manufacturing method thereof |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2726549A (en) * | 1953-03-27 | 1955-12-13 | Clay Adams Inc | Graduated measuring device |
| US2879207A (en) * | 1954-11-22 | 1959-03-24 | Millipore Filter Corp | Filtration and incubation unit |
| US3285296A (en) * | 1956-09-10 | 1966-11-15 | Beckman Instruments Inc | Pipette apparatus |
| FR1232474A (en) * | 1959-04-22 | 1960-10-10 | Manuf Generale De Caoutchouc V | Diaphragm valve system |
| US3166940A (en) * | 1961-03-23 | 1965-01-26 | Marjorie M Allisbaugh | Pipette |
| US3186236A (en) * | 1962-01-02 | 1965-06-01 | Frederick M Cox | Capillary tube blood collector |
| US3406573A (en) * | 1967-03-10 | 1968-10-22 | Dade Reagents Inc | Capillary pipette and adapter-holder therefor |
| BE788211A (en) * | 1971-09-16 | 1973-02-28 | Pall Corp | DEVICE AVAILABLE FOR FILTERING GAS |
| GB1463807A (en) * | 1973-03-01 | 1977-02-09 | Wellcome Found | Filters |
| JPS5020716U (en) * | 1973-06-21 | 1975-03-08 | ||
| FR2258896B1 (en) * | 1974-01-29 | 1978-03-17 | Loing Verreries | |
| US3932153A (en) * | 1974-02-14 | 1976-01-13 | John Byrns | Nebulizer bacteria filter |
| US3995496A (en) * | 1975-09-02 | 1976-12-07 | Bickford Albert G | Disposable mouth guard for pipettes |
-
1977
- 1977-12-16 CA CA293,200A patent/CA1066674A/en not_active Expired
-
1978
- 1978-01-12 JP JP233978A patent/JPS53100889A/en active Granted
- 1978-01-13 GB GB1413/78A patent/GB1595742A/en not_active Expired
- 1978-01-26 FR FR7802242A patent/FR2380059A1/en active Granted
- 1978-02-10 IT IT48017/78A patent/IT1103874B/en active
- 1978-02-13 DE DE19787804147U patent/DE7804147U1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1595742A (en) | 1981-08-19 |
| IT1103874B (en) | 1985-10-14 |
| DE7804147U1 (en) | 1978-08-03 |
| JPS53100889A (en) | 1978-09-02 |
| FR2380059A1 (en) | 1978-09-08 |
| IT7848017A0 (en) | 1978-02-10 |
| JPS5648208B2 (en) | 1981-11-14 |
| FR2380059B1 (en) | 1984-10-12 |
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