JPH056859B2 - - Google Patents

Abstract

A line pipette in which the diameter of its suction cylinder is longer in the direction transversal to the line than longitudinal to the line. In this way it has been possible to make their cross section area larger, yet without increasing their spacing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multichannel pipette comprising at least two liquid cylinders arranged in a line for simultaneously dispensing liquid into a plurality of containers, such as microtitration slides. .

BACKGROUND OF THE INVENTION Traditionally, standard titration slides with 8×12 wells are used, especially for optical measurement analyses. In that case, it would be necessary for the same amount of liquid to be placed and removed in multiple depressions of the slide. In order to speed up this process, multi-channel pipettes have been devised to accommodate, for example, eight wells at the same time.

Pipettes with a certain number of rows are known. For example, Finnish Patent No. 52025 (corresponding US Patent No.
4215092), Finnish Patent No. 60137 (corresponding British Patent No. 2045641), Finnish Patent No. 57704 (corresponding West German Patent No. 3008347), and Finnish Patent No. 58875
(corresponding US Pat. No. 4335621), as well as Finnish Patent Application No. 844906 (corresponding WD84/04056) are also available.

Looking at these documents, it can be seen that so-called multi-step pipettes are also disclosed which are capable of containing the same amount of liquid in several portions in one filling.

(Problems to be Solved by the Invention) The multi-step pipette shown in the above-mentioned document has a drawback that the more liquid that can be taken into the cylinder at once, the more the pressing stroke of the plunger increases. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pipette having a plurality of cylinders arranged in a straight line, which does not require an increase in the pressing stroke of the plunger even if the amount of liquid discharged at one time is increased.

(Means for Solving the Problems) In order to solve the above problems, the configuration of the present invention is to arrange the cross-sectional shapes of the liquid suction cylinders of a plurality of pipettes arranged in a straight line so that the diameters in the direction intersecting the arrangement line are arranged in a straight line. It will be larger than the diameter above.
In this case, the center-to-center distance between the cylinders is not increased.

Further, the plunger that acts on the cylinder is made airtight by an O-ring packing on the inner wall of the cylinder.

(Function) For example, align the pitches of the recesses arranged on a slide for optical measurement, arrange the pipette cylinders in a straight line, and adjust the diameter of each cylinder in the direction that intersects the arrangement direction. It is made larger and releases an increased amount of liquid with the same stroke of the cylinder.

(Example) The structure of the present invention will be explained based on the drawings showing the example. In FIG. 1, 1 is a handle;
2 is a pipette body, and 3 is a tip reservoir.

Eight cylinders 4 are arranged horizontally in a straight line in the pipette body 2, and a tip reservoir 3 is provided at each bottom end. These cylinders are integrally formed and attached to the pipette body. A plunger 5 is installed in each cylinder and is connected via a plunger rod 6 to a common supporting member 7.

The most notable feature of the cylinders 4 is that their diameter is larger in the direction perpendicular to the straight line in which the cylinders are arranged than in the direction of arrangement. When the cylinder is viewed in cross-section, its cross-sectional area can be increased without increasing the center-to-center spacing of the cylinder.

Possible cross-sectional shapes of the cylinder are listed in FIGS. 2a, 2b, 2c and 2d.

In order to make the plunger 5 airtight to the cylinder 4, an O-ring packing 9 is provided in a groove provided on the outer periphery of each plunger (FIG. 3). In this case, the partition wall 10 between each cylinder can be made thinner than in conventional designs since there is no need to provide grooves in the wall. This also means that it is possible to increase the diameter in the direction in which the cylinders are arranged.

Conventional packing methods can also be used in the present invention. Fig. 4 shows that the plunger is hermetically sealed with an O-ring fitted into a groove in the inner wall of the cylinder, but in this case as well,
It goes without saying that the cross-sectional diameter of the cylinders can be increased in the direction that intersects with the direction in which they are arranged.

The invention applies to pipettes of the single or multi-step type with a plurality of cylinders arranged, with a constant or controlled volume. Regarding plunger operation, plunger stroke adjustment, etc., conventional techniques can be applied as is to the pipette of the present invention.

The embodiment of FIG. 1 is a variable volume multi-step pipette, the operating mechanism of the handle itself of which is known from the above-mentioned Finnish Patent Application No. 844906.

The handle 1 can be removed from the pipette body. It is equipped with a rack having teeth on both sides, and a support rod attached to the holding member 7 meshes with the rack. Pressing the filling latch 15 raises the plunger. The filling latch 15 is connected to the teeth of another rack, the movement of which is transmitted via a pinion to one of the teeth of the support shaft. The plunger is moved downwardly by the release latch 16. The release latch 16 pushes down the impact piece provided on the other tooth of the support shaft downwardly along the shaft. The position where the impact pieces engage can be adjusted by an adjustment wheel 17. The guide groove of the adjustment wheel is adapted to move the impact piece to a desired position in conjunction with a lifter that disengages the impact piece.

(Effects) Since the present invention is configured as described above, in a pipette in which a plurality of cylinders are arranged in a line, the amount of liquid discharged can be increased without changing the cylinder pitch, and the monostep,
Alternatively, a horizontal pipette can be obtained in which the plunger stroke of one step does not need to be increased in any of the multi-steps. Furthermore, in a multi-step pipette, the effect of reducing the total stroke of the plunger can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway overhead view of a pipette according to the present invention, and FIGS. 2a, 2b, 2c, and 2d are sectional views showing the cross-sectional shape of the cylinder of the pipette according to the present invention. FIG. 3 is a partial sectional view taken along the direction in which the cylinders are arranged, and FIG. 4 is a sectional view showing another shape of FIG. 3. In the figure, 4... cylinder, 5... plunger, 9
...O-ring packing.

Claims (1)

[Scope of Claims] 1. At least two suction cylinders arranged in a straight line, having the same cross-sectional shape and an open bottom end, each having a plunger arranged in an airtight state,
A horizontal pipette equipped with a mechanism for moving the pipettes simultaneously and by the same distance, characterized in that the diameter of the cross section of the suction cylinder in a direction intersecting the horizontal direction is set larger than the diameter in the horizontal direction. 2. The horizontal pipette according to claim 1, characterized in that an O-ring packing is provided on the outer periphery of each plunger.