EP0182796A1

EP0182796A1 - Pipette type laboratory apparatus

Info

Publication number: EP0182796A1
Application number: EP19850901420
Authority: EP
Inventors: Walter Selzer; Hans Gall
Original assignee: Klaus F Mueller Pharmaverkaufsbuero
Current assignee: Klaus F Mueller Pharmaverkaufsbuero
Priority date: 1984-03-13
Filing date: 1985-03-09
Publication date: 1986-06-04
Also published as: WO1985004119A1

Abstract

L'appareil de laboratoire du type pipette est prévu pour la mesure de volume de fluides quelconques, il est notamment utilisable pour les analyses volumétriques et les recherches cliniques à des fins de diagnostic ainsi que pour le prélèvement et le dosage de certaines quantités de liquides. L'appareil est constitué de deux bras (A, B) articulés (3) ou coulissant l'un sur l'autre; l'un des bras présente à une extrémité une coupelle (1) de prélèvement de liquide et l'autre bras un couvercle pour la coupelle. L'appareil de laboratoire proposé permet des prélèvements exacts par pipette tout en éliminant les causes d'erreurs.The laboratory apparatus of the pipette type is intended for measuring the volume of any fluids, it is in particular usable for volumetric analyzes and clinical research for diagnostic purposes as well as for the sampling and dosing of certain quantities of liquids. The device consists of two arms (A, B) articulated (3) or sliding one over the other; one of the arms has at one end a cup (1) for withdrawing liquid and the other arm has a cover for the cup. The proposed laboratory device allows exact samples to be pipetted while eliminating the causes of errors.

Description

- Egg-like laboratory device

The invention relates to a pipette-like laboratory device according to the preamble of claim 1.

To date, liquid has been pipetted by means of piston stroke pipettes in a mechanical manner or with the aid of glass pipettes, in which the corresponding volume has to be set on the basis of applied ring marks. Possible errors must be taken into account. With piston piston pipettes, the mechanics can be misaligned or defective due to contamination, wear and tear or improper use, which in some cases leads to considerable pipetting errors which lead to incorrect measurement results and which are sometimes only recognized later.

In the case of glass pipettes, both in the case of capillary pipettes and in the case of larger glass pipettes, the volume to be pipetted is adjusted in that the liquid stock has to be adjusted to a certain ring mark attached to the pipette. This process requires dexterity and practice, an exact reading at eye level, careful attention to the type of pipette, so that no errors occur when blowing out, letting out, etc.

The chances of error if only one of the criteria mentioned are disregarded are high. In addition, working with these pipettes poses a risk of infection or injury, which makes the use of additional pipetting aids necessary.

The object of the invention is to simplify the pipetting of liquids in a substantial manner and to enable an exact and precise pipetting, excluding previous sources of error. This object is achieved by the technical teaching described in the characterizing part of patent claim 1, the device according to the invention working according to a completely new principle.

The volume to be pipetted is determined by a hollow or depression which is shaped accordingly for each size of pipette. It serves to take up an exact amount of the liquid to be pipetted, for example blood, serum, reagent and the like, without having to pay attention to a ring mark or the like. The liquid that protrudes upwards as a result of the surface tension after filling the hollow body and does not enter the target volume is pressed out laterally and forwards by closing the device through the upper part, by pressing the cover exactly onto the hollow body or pushing the arms together in a congruent manner become. Drainage of the liquid to the rear is prevented by sealing edges. The supernatant liquid squeezed out or pushed out in this way can be wiped off with a swab or the like, without running the risk of also removing liquid from the pipette-like laboratory device and thus unintentionally changing the desired volume, as was possible, for example, with previously conventional glass pipettes.

The front part of the pipette-like laboratory device is then introduced into the respective reaction solution and the contents, for example blood, are rinsed out by repeated opening and closing. The size of the device is such that with the sizes provided for sampling (up to approx. 100/200 microliters), it can also be inserted directly into so-called semi-micro cuvettes. The rinsing process is carried out only by alternately bnting or loading the two arms between the thumb and forefinger or by moving the arms. The opening and closing of the arms which are mounted with one another about a pivot point is brought about by the tension of the connecting strap which connects the two arms to one another. At the same time, a desired and necessary mixing process is carried out by gently moving the pipette up and down, which is supported by the two mixing lugs on the arms.

Up to now, the mixing process had to be carried out separately, which means that an additional device (spatula) and an additional work process are saved. The device is discarded after use, so that any contamination of the reaction mixture, carry-over of sample material, risk of infection, risk of contamination by cleaning agents, signs of wear and other possible errors are eliminated.

A special liquid-repellent treatment or coating of the front ends of the arms of the device, both externally and internally, additionally prevents liquid from adhering, which also means that the device is immersed in the liquid to be pipetted, for example reagent, with subsequent transfer into closed state and leakage is possible by simply opening or sliding. The pipetting process carried out in this way is not only considerably simplified in terms of handling, but also freed from practically all possible errors. In this area of application, the device can also be used for serial pipetting.

A coating of the cavity or depression, for example, with substances which inhibit blood clotting and similar active substances, as is already customary in the case of glass pipettes, is of course possible. Use in the sterile area is also possible due to the fact that the device can be sterilized.

The pipette-like laboratory device according to the invention not only offers all possible uses, but also simplifies the pipetting process considerably, with the elimination of practically all application-related error possibilities, such as had previously been accepted. All in all, this results in a considerable improvement in the measurement and analysis results, which is also of particular economic interest in the primary target group of users, medical, clinical-chemical laboratory, while at the same time reducing the expenditure of time and the potential risk of infection or injury.

In addition, there are no additional costs, for example for disposable items such as pipette tips (necessary in the case of piston-stroke pipettes, stirrers etc.).

The device according to the invention is suitable for dispensing or pipetting technology in the volume range can be covered by the pipette, to simplify decisively, to make it more error-free or less dangerous and to change it in such a way that it is seriously positive.

The following description of preferred embodiments serves in conjunction with the accompanying drawings to further explain the invention.

Show it:

1 shows a pipette-like laboratory device with arms mounted around a fulcrum schematically from the side and from above in the open state, including in the firmly closed or folded state,

2 shows the application of the device according to the invention according to FIG. 1 in a schematic representation,

3 shows the introduction of the device into a measuring cuvette and the mixing with the measured liquid;

4 shows a pipette-like laboratory device in a perspective view with two arms which can be moved one on top of the other in a separated state,

5 shows the same device according to FIG. 4 in the assembled state with arms and

Fig. 6 shows a * cross section through the slidably arranged arms ^{' of} the device.

According to FIG. 1, the device has two arms or branches A, B, which are connected to one another by means of an articulated connection or simply by means of a notch 3 are connected. At the end of arm A is the cavity or depression 1, which comprises a certain volume. The end of the arm B has a lid 5 which fits exactly on the recess 1. 4 and 7 denote sealing edges, while 2 and 6 represent small elevations at the ends of the arms A, B, which have the function of mixing lugs.

The same device * is shown in FIG. 2, the reference symbols 1 to 7 and A and B having the same meaning as in FIG. 1. The sample material 8, for example capillary blood, whole blood, serum and the like, is placed in the cavity 1 and then the device is pressed together with the index finger 9 and thumb 10 so that a precisely measured volume is included. Then the device is placed in a measuring cuvette 11 with reagent and the measured volume of the sample material is put into the measuring cuvette by loosely holding the device and gently shaking it into the reagent liquid. Leaking and mixing of sample material and reagent takes place in one operation. The device is then discarded.

3 schematically shows the pipetting of reagent liquid from a storage container 12 into a measuring cuvette 13.

4 shows an embodiment of the pipette-like laboratory device according to the invention with arms A, B sliding and sliding on one another in a separated state with the cavity 1 for the material to be pipetted and the hooks 16, 17 engaging in the slots 14, 15 18, 19 are the outer grooves on the arms A, B designated.

FIG. 5 shows the same device according to FIG. 4 in the assembled state, the reference symbols having the same meaning and

6 finally shows a cross section through the arms A, B with the hook 16 engaging in the slot 14, as a result of which the two arms A, B are held on one another in a sliding manner.

Claims

Pipette-like laboratory device

P a t e n t a n s r u c h e

Pipette-like laboratory device for measuring the volume of liquids of all kinds, in particular for use in dimensional analysis and in the clinical field for diagnostic examinations as well as for taking and dosing certain amounts of liquid, characterized in that it has two tweezers resiliently mounted around a pivot point (3), has arms or branch (A, B) connected to one another or separately from one another and displaceable one on the other in the longitudinal direction and held together by hooks (16, 17) sliding in slots (1, 15), one arm (A ) at its front end a volume or recess (1) with exact volume and the other arm (B) at its front end formed as a cover (5) smooth the recess (1) of the former arm (A) Contains surface which, when the two resilient arms (A, B) are pressed together or when they are shifted congruently, has a complete abdic caused.

2. Laboratory device according to claim 1, characterized in that the arms (A, B) have sealing edges (4, 7) on the inner sides of their front ends.

3. Laboratory device according to claim 1 and 2, characterized gekenn¬ characterized in that the arms (A, B) on the outer sides of their front ends have mixing lugs (2, 6).

4. Laboratory device according to claim 1 to 3, characterized gekenn¬ characterized in that the slidably arranged arms (A, B) have on their outer sides grip grooves (18, 19).

5. Laboratory device according to claim -1 to 4, characterized gekenn¬ characterized in that the slidably arranged arms (A, B) with the hooks (16., 17) engaging slots (14, 15) are wedge-shaped or similar are.

6. Laboratory device according to claims 1 to 5, characterized in that the ends of the arms (A, B) to be immersed in the liquid are provided with a liquid-repellent coating.