FI73368C - Radpipett. - Google Patents

Description

73368

Rivipipettl

The invention relates to a multichannel pipette with at least two liquid cylinders arranged in a row. The pipette is used to dispense liquid simultaneously into several containers 5, for example a microtiter plate.

In particular, standardized 8 x 12-well microtiter plates are commonly used for photometric analyzes. It is often necessary to dispense or remove the same amount of liquid from several wells of the plate. In order to speed up the work 10, multichannel pipettes have been developed, with which, for example, the dosing of eight wells can be performed simultaneously.

Some series of pipettes are known, for example, from patent publications FI 52 025 (corresponding to US 4215 092), FI 60 137 15 (corresponding to Gb 2045 641), FI 57 704 (corresponding to DE 3008 347) and FI 58 875 (corresponding to US 4335 621) and from public patent application EN 84 ^ 1906 (corresponding to WO 84/04056). The so-called publications are also known. multistage pipettes capable of dispensing several nts-20 volumes of the same size in a single filling.

A disadvantage, especially in multistage pipettes, is that when an attempt is made to increase the amount of liquid taken into the liquid cylinder at a time, the movement of the pistons becomes uncomfortably large.

It is therefore an object of the present invention to provide a in-line pipette in which the stroke length of the pistons can be shortened.

In the pipette according to the invention, it is essential that the diameter of the cylinders is longer in the transverse direction than in the longitudinal direction. In this way, the cross-sectional area of the cylinders has been increased without increasing the distance between them, however.

The invention is further illustrated by the accompanying drawings. Fig. 1 shows a partially opened perspective Illustration of a pipette according to the invention, Figs. 2a, t, c and δ cross-sectional shapes of cylinder-35 blades, Fig. 3 a row sectional view of the cylinder set of the pipette of Fig. 1 and Fig. 4 an alternative to the embodiment of Fig.

73368

The main parts of the pipette according to Figure 1 are the handle 3, the body 2 and the tip containers 3.

The body has eight cylinders 4 arranged in rows, to the lower end of which the tip tanks are attached. The entire cylinder-5 riser set is made in one piece and attached to the frame. Each cylinder has a piston 5 · The piston rods 6 are suspended on a common support 7 ·

The most important thing about the cylinders 3 is that their diameter is longer in the transverse direction than in the longitudinal direction. Thus, the cross-sectional area of the cylinders 10 has been increased without increasing the distance between them.

Figures 2a, b, c and d show some possible cylindrical cross-sectional shapes.

In order to seal the caps 5 to the cylinders 4, there is a C-ring seal 9 in the groove 8 on the outer surface of each piston 15 (Fig. 3). In this way, the partition wall 10 of the cylinders can be made thinner than in the conventionally used solution, in which the 0-ring is in a groove on the inner surface of the suction cylinder. In this way, the diameter of the cylinders can also be increased in the longitudinal direction of the row 20.

A conventional piston sealing solution can also be used in the pipette according to the invention. In the solution according to Figure 4, the pistons 11 are sealed to the suction cylinders so that the C-ring 12 is in a groove 13 in the wall 25 of the cylinder. However, the diameter of the pistons is larger in the transverse direction than in the longitudinal direction of the row.

The invention can be applied to single or multistage series pipettes of constant or control volumes. The known solutions for moving the pistons and adjusting their stroke lengths are as such applicable to the pipettes according to the invention.

The application according to Fig. 1 is a multi-step pipette with adjustable volumes, the operating mechanism of the handle of which is known per se, for example from the above-mentioned patent application-35 according to FI 84 4906. The handle part 1 is detachable from the body. Inside it is a toothed rod with double-sided teeth, to which the support arm 14 is connected.

73368 The tail is moved up by pressing the fill button lp. The fill button is attached to a second rack, the movement of which is transmitted to the second toothing of the support arm by means of a gear. The pistons are moved downwards by means of the lifting button 16 of the an-5. The dispensing button pushes the arm downwards with the aid of a striker resting on the second tooth. The engagement of the striker with the teeth is adjusted by means of the adjusting wheel 17. The guide groove on the adjusting wheel is associated with a lifting lever which lifts the striker 10 off the tooth at the desired point.

Claims (2)

A row pipette comprising at least two suction cylinders (2) with an open cross-section of the same cross-section arranged in a row, each of which has a movable sealed piston (5), and an apparatus for moving the pistons the same distance simultaneously, characterized in that the diameter of the suction cylinder is longer than the length of the line. Pipette according to Claim 1, characterized in that an O-ring seal (8) is embedded in the outer surface of each piston.