Measuring and testing – Sampler – sample handling – etc. – Capture device
Reexamination Certificate
1999-08-25
2002-12-31
Noland, Thomas P. (Department: 2856)
Measuring and testing
Sampler, sample handling, etc.
Capture device
C073S864140, C073S864160
Reexamination Certificate
active
06499364
ABSTRACT:
FIELD OF THE INVENTION
The object of this invention is a tip with a mantle wall defining a sample space, for receiving a liquid sample, the tip having a first open end to be inserted into a liquid and a second open end for attaching the tip to a suction device, such as a mechanical or electronic pipette, intended for dispensing, transferring, diluting, titrating, mixing, or a combination of all, or some of these operations.
The object of the invention is also a method for dispensing, transferring, diluting, titrating, mixing, or a combination of all, or some of these operations with a suction device, such as a mechanical or electronic pipette having an end part, which encloses a cylindrical space having a reciprocating means, such as a plunger, and having a removably attached tip.
The said suction devices comprise a body and an associated end part, the open end of which being directed away from the body for removably attaching a disposable tip having a sample space for receiving a liquid sample, the end part encloses the cylindrical space having a reciprocatingly movable means, a plunger, for receiving a sample and for removing it therefrom.
When in the following description the words ‘suction device’ or ‘pipette’ are used, they generally mean all types of suction devices defined above, which suction devices function as pipettes, dispensers, diluter, titraters, or mixers, or in addition as a combination of all or some of these operations. A mechanical or an electronic pipette can be a manually operated separate device or part of some apparatus, of an analysing device, etc.
DESCRIPTION OF THE RELATED ART
Over approximately the past three decades pipettes have been in use having attached liquid reservoirs, that is pipette tips, from which liquid has escaped to the inner parts of the pipette, for example due to careless operation of the pipette, or in the form of liquid molecules vaporized from the liquid. The contamination of the inner parts of the pipette has jeopardized labour safety and reduced or even completely terminated the reliable operation of the pipette itself. Naturally this cannot be accepted in laboratory work, which has to be precise as well as safe to users and patients. Also in scientific or in other such work this is not allowed.
Due to these problems pipette manufacturers recommend that the pipettes are disassembled and cleaned at regular intervals by the pipette users. In this procedure almost always also the plunger and the gasket of the pipette are re-lubricated and often also the pipette has to be re-calibrated, i.e. the pipetted, dispensed etc. liquid volumes are set to correspond to the volumes set on the scale of the pipette. This disassembling and reassembling of the pipette, in addition to being an inconvenient and laborious procedure, does not guarantee that the pipette would not contain infection agents or other contamination such as DNA- and RNase-contamination which interferes with PCR-work. Therefore some pipette manufacturers have started to manufacture pipettes, which are claimed to be sterilizable in an autoclave. Sterilization in the autoclave does not, however, remove DNA- and RNase-contamination from the pipette parts. It is a very tedious operation and often the operation itself damages parts of the pipette to such an extent that the pipette will not function sufficiently accurately and reliably any more. When the pipette is used after the sterilization, it is possible that it will be contaminated already with the first pipetting.
U.S. Pat. No. 5,406,856 discloses a suction device which is meant to be used with such disposable tips, which have a tip portion to be inserted into a liquid, the tip portion having an opening for taking a liquid sample and removing it and in which disposable tips the part to be adapted onto the end of the body of the suction device is closed towards the suction device. The form of this closed part and simultaneously its volume can be changed with a means within the end part of the body of the suction device. In this solution the contamination can be prevented, but the disposable tip used is a special tip.
U.S. Pat. No. 4,444,062 discloses a multichannel suction device having a flexible membrane mounted between the body of the suction device and an attached tipstand so, that the rods in the plunger movable within the body of the suction device come into contact with the membrane, when the plunger is pushed downwards. In this solution the membrane is secured either on the undersurface of the body or on the upper surface of the tipstand or two membranes are used of which the first one is secured on the undersurface of the body and the second one on the upper surface of the tipstand. The tipstand itself is mounted to the body with a screw connection. In an embodiment of this invention, the tipstand assembly consisting of a tipstand with attached tubes and tips attached to these and a membrane secured onto the upper surface of the tipstand can be one disposable moulded plastic unit which is mounted to the body of the suction device with a suitable quick connection method. In this publication, nothing is disclosed of the removal of the tipstand, tipstand assembly, or its parts from the body with a movement of the plunger or some other means, such as a tip remover or other such means.
BRIEF SUMMARY OF THE INVENTION
The disadvantages cited above can be avoided by using the solution for the disposable tip according to the invention. It is characterizing for the tip according to the invention that the tip is provided with a membrane means closing the gas and liquid passage in a gas and liquid tight manner from the first end of the tip to the suction device, when the tip is attached to the suction device, the membrane means comprising a membrane made of a gas and liquid impermeable, flexible, reversibly deformable material. The solution according to the invention prevents liquids to be dispensed and/or gases vaporizing therefrom from entering the inner parts of the pipette. In addition, the tip according to the Invention can be removed with the movement of the plunger or other similarly functioning means, which increases the ergonomy of the use of the pipette and working safety.
The object of the invention is also a method, which is characterized in that the reciprocatingly movable means within the cylindrical space enclosed by the end part of the suction device, is brought into contact with a membrane means in the sample space of the tip, the membrane means comprising a membrane, which is made of a gas and liquid impermeable, flexible, reversibly deformable material, for changing the volume delimited by the membrane from the sample space of the tip for taking a sample and/or removing it, and that the tip is removed from the end part of the suction device by translating the movement of the means to the tip.
The suction device itself used with the disposable tip, can be as such a known manually operated or e.g. electrical, and it can be independently operated or functioning as a part of some apparatus, e.g. pipette.
The disposable tip according to a preferred embodiment of the invention is attached to the end part of the suction device preferably against the inner wall of the cylindrical space within the end part with a friction joint. In another preferred embodiment according to the invention the disposable tip is attached e.g. with a friction joint against an inner, conical surface widening towards the end of the end part. The said cylindrical space or the said conical surface can also be provided with shoulders or projections, against which the disposable tip comes into contact when attached.
The disposable tip according to another preferred embodiment of the invention can also be attached onto the end of the end part of the suction device by using a suitable mounting means, such as a sleeve, attachable e.g. with a friction joint, and to which the disposable tip is attached e.g. with suitable holding means, such as projections.
Still in another preferred embodiment of the invention, the tip according to the invention ca
Biohit Oyj
Birch & Stewart Kolasch & Birch, LLP
Noland Thomas P.
LandOfFree
Tip for a suction device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tip for a suction device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tip for a suction device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2936407