MICROPIPETTING APPARATUS

摘要

1363540 Syringes F HOFFMANN-LA ROCHE & CO AG 15 Aug 1972 [13 Oct 1971] 38048/72 Heading F1R [Also in Division G1] Apparatus for the simultaneous pipetting of a plurality of equal amounts of liquid of the order of magnitude of a microlitre comprises a plurality of cannules fastened in a carrier plate which is covered by a membrane the free surface of which is covered by a perforated plate provided with indentations which are in communication with a suction chamber and which are disposed in such a way that each indentation corresponds to a cannula and, in use of the apparatus, can determine the volume of liquid pipetted by the cannula. As illustrated in Figs. 1 and 3, cannules 1, carrier plate 2, membrane 3, perforated plate 4 and suction chamber 5 are secured together by means 8 to form a cannula plate 10 which is attached to a support 11 provided with a carrier plate 13 for supporting a microtitration plate 12 having recesses filled with culture media or another plate (not shown) bearing agar or other nutrient medium; in operation of the apparatus, vacuum applied by a foot pedal 14 is transmitted to each indentation 6 via a hole 7 thereby to retract the membrane into the indentation. As illustrated in Fig. 2, the perforated plate may be provided with additional indentations 9 which serve to improve the separation of the protrusions produced in the membrane when vacuum is applied. The cannules may be arranged in staggered relationship.