摘要 |
The invention relates to an automatic pipetting device, which comprises at least two pumping units of different capacities and a liquid line, said liquid line opening on one side into a rinsing liquid reservoir and on the other side into a pipetting needle. In order for one pumping unit to be able to execute a pipetting cycle with small volumes at high stroke resolution and the other pumping unit to be able to execute a rinse cycle with large volumes, and to make the pumping units as space-saving, as low-maintenance and as inexpensive as possible, it is proposed according to the invention to drive the pistons of the at least two pumping units synchronously by a piston drive device and to arrange the point at which the largest working chamber is connected to the liquid line closer to the rinsing liquid reservoir than the point at which the working chamber of the at least one other pumping unit is connected to the liquid line, wherein moreover a 3-way valve is arranged on the liquid line at the point at which the largest working chamber is connected to the liquid line. |