DE1598188A1 - Automatic pipetting system for series examinations - Google Patents

Description

Description.

The innovation relates to an apparatus that can be used for pipetting Freely adjustable fitness amounts and immediately following dilution: can also be used with a variable volume. Accessories-one Transport unit and a picker enable a fully automatic process of Serial examinations.

So far, automatic pipetting devices have been manufactured, whereby the Diverting the liquid through valves is done, moving the spril: z through Electric motors. These devices have the disadvantage that they clog the valves malfunctions can easily occur and the required accuracy is not is guaranteed. Moving the syringes by electric motors requires one considerable technical effort. The transport unit and a picker were in not yet made this way.

The valveless system of the system described below settles only made of glass and Teflon together and results in excellent reproducibility. Aggressive and radioactive liquids can therefore be pipetted. An accompanying conveyor belt for test tube racks with test tubes and a Extractors enable a fully automatic process of pipetting for series examinations.

Figure 1 shows the structure of the pipetting machine Figure 2 den Course of the compressed air flow Figure 3 the construction of the syringe piston Figure 4 the transport unit Figure 5 the extractor.

Automatic pipetting machine> Figures 1 and 2.

There are 2 double-acting compressed air cylinders on a base plate (1) (2) attached. This is on a plate (3) that is perpendicular to the base plate Glass pipe system (4) with a movable disk valve and a horizontal double-acting one Pressure cylinder (9) permanently mounted. The syringe barrels (5) are spherical ground and corresponding clamps movably connected to the pipe system. The syringe plunger (6) are also connected to the plungers of the pressure cylinders by means of ball joints. The adjustable stops (7) are located on the rams of the pressure cylinders, with which a certain stroke of the pressure cylinder can be set. The disc cock (8) is actuated by the pressure cylinder (9).

The course of the compressed air flow can be seen in Figure 2. At (1) the compressed air is taken from a built-in compressor or from a The compressed air line is taken and via the solenoid valve (2) via a distributor (3) fed to the compressed air cylinders. The distributor will by means of a adjustable electric motor controlled by a Maltese cross and limit switch. Above the line (5) the compressed air goes into the lower part of the pressure cylinder 4. This the plungers of the pressure cylinders 4 move upwards. After a few seconds it will the compressed air is passed through the line (7) into the compressed air cylinder 8 and the plunger this pressure cylinder moves to the right. After another few seconds, the air will be passed through the line 9 in the upper part of the pressure cylinder 4 and the plunger these pressure cylinders move downwards. After a third period of time then the air is passed into the right part of the pressure cylinder 5 via this line (10) and the ram of this pressure cylinder moves to the left.

When the syringe plunger goes down, this becomes the dilution liquid sucked in via the nozzle (10) Fig. 1 and the sample through the nozzle (11) Fig. 1. After turning the disc stopcock (turn by 900) and upward moving syringe plunger the sample and the dilution liquid are ejected through the nozzle (11).

Syringe plunger, Figure 3.

Two nuts 2 and 3 are screwed onto the threaded stem (1), of which one serves as a lock nut, on it is a washer and a cylindrical one Part 4 made of Teflon with a screwed-in groove and smooth passage pushed on. part 5 is similar and is also made of Teflon and has a threaded blind hole. Between These parts are a cylindrical sleeve (6) made of metal or hard plastic. Elastic O-rings (7) are inserted into the grooves of the Teflon parts. Becomes the mother (3) is tightened, the O-rings are pressed together and press the sealing lips the Teflon parts against the glass cylinder. Since Teflon has cold flow, this is used Way achieved a good seal.

Transport unit, Figure 4.

The two rollers (2) are mounted on a ram frame (1). Above These rollers run a 7 cm wide conveyor belt (3). One of the roles is played by a reversible gear motor (4) driven by a drive chain or belt. The motor is fed via a transistor-controlled power supply unit (5). In a frame (6) stores the test tube rack (7) on the conveyor belt and is either from moved right to left or left to right. Touch while moving the test tubes press the button (8) which sends a pulse to the control unit (9) gives. Switching the motor on and off is controlled via R-C elements and relays and thus the dwell time of the individual test tubes in front of the button. By A changeover switch can be used to switch the movement to manual or automatic mode.

Extractor, Figure 5 The extractor has the task of a pipette (1) to move vertically (2) or in a rectangle (3). The following construction was used for this Executed: The slide (5) moves on the frame (4) through the motor (6) driven spindle (7). The movement is limited by the limit switch The limit switch can be adjusted, whereby the stroke can be changed as required can. The device for the horizontal movement is built on the slide (5). The fixed spindle (9) is driven by the motor (10). This moves the carriage (11), which is stored in: 2 guide rods horizontally. On the sledge (11) the extraction rod (12) is firmly mounted. The movement is controlled by the limit switches (13), one of which is adjustable. The entire sequence of movements is controlled via R-C elements and relays. The extractor is by means of a sleeve attached to a tripod (14) and can therefore be adjusted to any height.

III All 3 devices can be linked to each other by cable connections that, for example, the following pipetting and filling process are carried out can be. A double-row test tube rack is placed on the conveyor belt. In the front row there are test tubes filled with a sample, the back row is empty, these should be filled with sample and a certain amount of dilution liquid be filled.

The transport belt is started, it moves until the 1. Test tube touches the button. The button gives the orderer the command, to drive down. When the dispensing pipette has reached the lowest point, there is the sampler gives the pipetting device the command to aspirate. The pipetting device removes a certain amount of the sample and at the same time a certain amount of dilution liquid from a storage bottle. The pipetting device then gives a command to the extractor.

This goes up, pushes back and dips into the adjacent one empty test tube. If the withdrawer has again reached the lowest point, gives he sends a command to the pipetting device. The pistons go up and push the previously sucked up liquids. The pipetting device now gives a command the owner. This drives up and forward; has he reached this point he gives a command to the conveyor belt to start. As soon as the next test tube comes in front of the button, the conveyor belt is stopped and the process starts from New. Depending on the setting of the pipetting device and the dispenser, others can desired movement sequences can be carried out.

Claims (11)

Protection claims 1. Automatic pipetting system for series examinations characterized in that the suction and ejection of the liquid with Syringing happens but no valves are used. Diverting the liquid is carried out by a three-way flat valve. 2. Apparatus according to claim 1, characterized in that the movement processes can be operated by means of controlled compressed air. Either by taking it from a Compressed air line or by means of a built-in compressor. 3. Apparatus according to claim 1 and 2, characterized in that the The plungers of the syringes are provided with elastically mounted Teflon seals. 4. Apparatus according to claims 1-3, characterized in that the supply and discharge is arranged above the syringes and the apparatus itself vented. 5. Apparatus according to claim 1-4, characterized in that Adjustable stops on the plungers of the pressure cylinders that actuate the syringes by means of which precise, reproducible volumes can be set. 6. Apparatus according to claims 1-5, characterized in that the time the switching of compressed air from the pressure cylinders for the syringes to the pressure cylinder can be regulated to move the disc valve. 7. Apparatus according to claims 1-6, characterized in that the pipetting system consists of an automatic pipetting device, a transport unit and a dispenser. These devices can be coupled with cable connections and the movement processes, those for sucking in, ejecting the liquid, as well as for transferring from a glass to the others are necessary, are controlled by limit switches, R-C elements and relays. 8. Apparatus according to claim 7, characterized in that the devices switched to manual or automatic mode by actuating a switch can be. 9. Apparatus according to claim 7 and 8, characterized in that the Automatic pipetting machine by actuating a switch on an operation (suction or ejection) or in 2 work steps in a row (suction and ejection) can be asked; and that the withdrawer can also press a Switch to a vertical movement only or to a rectangular movement can be. 10. Apparatus according to claim 7 and 9, characterized in that the vertical and lateral movement carried out by the extractor, continuously adjusted can be. 11. Apparatus according to claim 7, 9 10 characterized in that the Extractor is attached to a tripod and set to any height can be.