US3463013A

US3463013A - Pipetting device for tissue culture dissemination

Info

Publication number: US3463013A
Application number: US647683A
Authority: US
Inventors: Robert J Reedy
Original assignee: US Department of Health and Human Services
Current assignee: US Department of Health and Human Services
Priority date: 1967-06-21
Filing date: 1967-06-21
Publication date: 1969-08-26
Anticipated expiration: 1986-08-26

Description

R. J. REEDY Aug. 26, 1969 PIPETTING DEVICE FOR TISSUE CULTURE DISSEMINATION Filed June 21. 1967 INVENTOR ROBERT J. REEDY ,ZMMZ

ATTORNEY United States Patent 3,463,013 PIPE'ITING DEVICE FOR TISSUE CULTURE DISSEMINATION Robert J. Reedy, Silver Spring, Md., assiguor to the United States of America as represented by the Secretary of the Department of Health, Education, and Welfare Filed June 21, 1967, Ser. No. 647,683 Int. Cl. G01n 1/14 U.S. Cl. 73-425.6 6 Claims ABSTRACT OF THE DISCLOSURE The present disclosure relates to a hand-operated pipetting device utilizing sources of superatmospheric pressure and vacuum, which device is particularly suitable in tissue culture dissemination. The device is adapted to receive a pipette and resultant combination is then operated to aspirate a tissue culture into the pipette by means of the source of vacuum, and then for ejecting the previously aspirated culture from the pipette into a suitable flask by use of the source of air pressure. Vigorous splashing of the cell suspension breaks up the clumps into smaller units, thereby creating conditions of greater tissue.

The present invention relates to a hand-controlled pipetting device and, more particularly, to such a device for use in the dissemination of tissue culture.

Until the present time the most common pipetting technique still conventionally used in most laboratories has involved mouth-pipetting. The unsatisfactory features of mouth-pipetting have been long known, particularly the danger to the operator, the slowness of the operation, and the lack of sanitary conditions, and accordingly, many substitutes for the common mouth pipette have been suggested. Generally, however, except for the use of a rubber bulb or syringe in conjunction with a pipette which has found some acceptability, the various proposals have not been generally adopted and have been, for one reason or another, unsatisfactory. Furthermore, the previous pipetting techniques have not been entirely satisfactory for the dissemination of tissue culture since it is desirable to break up the tissue into the smallest possible particles and the generally used pipetting techniques have not accomplished this desired result.

Accordingly, it is an object of the present invention to obviate the deficiencies of the prior art, such as indicated above.

It is another object of the present invention to provide a hand-operated pipetting device of improved utility.

It is another object of the present invention to improve the speed of pipetting, improve the conditions of sanitation associated with pipetting, and to safeguard the technician who is carrying out the pipetting.

It is another object of the present invention to effect tissue culture pipetting while simultaneously breaking up the tissue clumps into smaller units.

It is another object of the present invention to provide a pipetting device which can be easily hand-held and operated with one hand which will accomplish the above objects.

These and other objects and the nature and advantages of the present invention will be more apparent from the accompanying drawing, wherein:

FIG. 1 is a perspective view, partly broken away, of a pipetting device in accordance with the present invention.

A pipetting device shown generally at 10, comprises a body member 12 having a generally elongated axial bore 14 therein having an outer end 16 and an inner end 18. The bore 14 is adapted to receive the open end 20 of a conventional pipette 22.

3,463,013 Patented Aug. 26, 1969 In order to provide an air-tight seal between the outer wall of the pipette 22 and the inner wall of the bore 14, it is generally desirable to utilize some type of sealing means such as the gasket 24, which is preferably formed of synthetic rubber, such as neoprene. Other types of seals may also be used and it may be desirable to utilize an O-ring which Will fit between the outer wall surface of the pipette 22 and the inner wall surface of the bore 14. The gasket 24 may effect its sealing by abutting against the open end 20 of the gasket 22.

The body member 12 is provided with a first air passageway 26 whch communicates with the bore 14 at one end and is connected at the other end with a suitable source of vacuum through conventional means such as a rubber or plastic hose 28. Disposed along the length of the first passageway 26 is a first valve (not shown) carried within a valve housing 30.

The valve within the valve housing 30 is biased to maintain the passageway 26 closed. In order to open the valve within the housing 30, it is necessary to merely depress a suitable valve control element 32, which projects outside the housing 30, to effect the opening of the passageway 26.

The body member 12 is provided with a second air passageway 36 Which also communicates With the bore 14 and is connected at its opposite end to a suitable source of air under superatmospheric pressure via a hose 38. As with the first passageway 26, the second passageway 36 is provided along its length with a valve carried Within the valve housing 40 and operable with a valve control element 42, which projects outside the housing, used to open the valve, thereby opening the passageway 36 by merely depressing the valve control element 42.

The precise structure of the valves carried within the

housings

30 and 40 is not the subject of the present invention and any suitable valve mechanisms may be used, such mechanisms being well known and available commercially. It is only necessary that such valves be biased to the closed position and that they be preferably operated by depressing the

valve control elements

32 and 42.

It is the desirable feature in accordance with the present invention that the

valve housings

30 and 40 and the respective projecting control elements 32 and 42 'be located closely adjacent one another so that as the device 10 is grasped in one hand, the

elements

32 and 42 may be easily depressed with the fingers of one hand in sequence as desired.

Because air under superatmospheric pressure is used in the operation of the device 10 in accordance with the present invention, it is generally desirable to provide the body member 12 with suitable means to prevent the pipette from being expelled from the bore 14. Such means may comprise a suitable retaining screw 34 extending from the outer surface of the body member 12 to the bore 14. A detachable stainless steel pin or other retaining means may be utilized in place of the retaining screw 34.

During use, it is generally desired to place a cotton plug in the bore 14 between the end of the pipette 20 and the

passageways

26 and 36. In order to prevent such cotton plug from being drawn into the passageway 26 during the application of vacuum, it is desirable to provide a stainless steel screen 44 at the end 18 of the bore 14.

The device 10 may be formed of any suitable material such as high chromium stainless steel, brass, titanium, or plastic materials, such as glass reinforced resins, nylon, polycarbonate resin, acetal resin, or others.

In the preferred embodiment the device is made of brass and measures 3 /2 x 1 /2 inches. The bore 14 is provided to receive a 10 ml. pipette for aseptic introduction into a tissue culture flask. The

passageways

26 and 36 at their extreme outer ends are provided with suitable fittings 26 and 36', respectively, for attachment of /s inch gum rubber hoses 28 and 38. Preferably, a source of air pressure of about 5-8 pounds per square inch is attached to the rubber hose 38 and a vacuum of about 5 pounds per square inch is attached to the rubber hose 28. However, greater or lesser amounts of pressure and vacuum can be used according to the dexterity of the operator.

The device may be operated as follows:

The entire apparatus, including the hoses, may be first sterilized, such as by autoclaving, prior to use thereof. A sterile ml. pipette is inserted and locked into the device utilizing the set screw 34. The rubber hoses are connected to a suitable superatmospheric air and vacuum supply and properly adjusted to an air pressure of about 8 pounds per square inch and a vacuum of about 5 pounds per square inch. The pipette is aseptically introduced into a previously prepared tissue culture flask containing cells which are to be dispersed and broken up into individual cell units. The operator, holding the device 10 in one hand, merely depresses the vacuum valve control element 32, thereby drawing about 5-6 ml. of suspension into the pipette. The operator immediately releases the vacuum valve control element 32, thereby causing the vacuum valve to automatically close, and then depresses the air pressure valve control element 42 and the suspension is forcibly ejected from the pipette into the flask. By moving the pipette around the sides of the flask while the suspension is being expelled, the tissue flakes adhering to the sides of the flask thus may be washed down. Vigorous splashing of the cell suspension breaks up the clumps into smaller units, thereby creating conditions of greater tissue dispersion.

What is claimed is:

1. A hand-operated pipetting device for disseminating tissue culture comprising:

a body member having an elongated cylindrical bore therein for receiving therein the large open end of a pipette;

means for providing a generally air-tight seal between the outer surface of said pipette and the inner surface of the bore of said body member;

first air passageway means communicating with said bore for connection to a source of vacuum;

first hand-operable valve means including a first valve housing for opening said first passageway for controlling the passage of air from said bore to the source of vacuum, said valve means having a first control element projecting outside said first valve housing, and said valve means being biased in the closed position;

second air passageway means communicating with said bore for connection to a source of air under superatmospheric pressure; and

second hand-operable valve means including a second valve housing for opening said second passageway for controlling the passage of air from the source of superatmospheric air to said bore, said valve means having a second control element projecting outside said second valve housing, and said valve means being biased in the closed position.

2. A device in accordance with claim 1, wherein said sealing means comprises a flexible gasket located within said bore at the large open end of the pipette.

3. A device in accordance with claim 1, further comprising a screen at the inner end of said bore adjacent the mouth of said passageway means.

4. A device in accordance with claim 1 wherein said valve control elements are closely adjacent whereby said valve means are both operated by the fingers of one hand when said body member is grasped to effect operation of said device.

5. A device in accordance with claim 4 wherein either of said passageways are opened by depressing said valve control elements.

6. A device in accordance with claim 1, further comprising means to retain the pipette within the bore of said body member.

References Cited UNITED STATES PATENTS 2,153,105 4/1939 Szecsi 73-425.6 2,376,231 5/1945 Cohn 73425.4 2,994,349 8/1961 Denos.

S. CLEMENT SWISHER, Primary Examiner