MULTI-CAVITY WASHING APPARATUS

摘要

Apparatus for washing microtitration plates comprises a carriage (16) which runs beneath a liquid dispensing head (46). Rinsing fluid supply nozzles (48) and suction nozzles (50) project downwardly from the head (46). The nozzles can be lowered into a row of wells in the plate (14) by movement of the head (46) about a pivot (55). The carriage (16) containing the plate (14) is moved under the nozzles to align a row of wells beneath them in order to perform a washing operation. The washing process comprises filling the wells with rinsing fluid from the supply nozzles (48) and evacuating the fluid by means of the suction nozzles (50). The raising and lowering of the dispensing head and the movement of the carriage are effected by stepper motors (36 and 57) controlled by a preprogrammed microprocessor. The microprocessor offers several different washing cycles from which the user can select one suitable for his requirements. In one cycle the carriage is caused to move to and fro whilst the suction nozzle is evacuating the wells so that the side walls of the well are brought up to the nozzle enabling the fluid that tends to collect in the corners of the wells to be removed. In another cycle the suction nozzle is positioned just above the level of the upper surface of the microtitration plate. Rinsing fluid is supplied to the well whilst suction is supplied to the well. The well is overfilled without the rinsing fluid overflowing into adjacent wells because of the section nozzle. In this way the wells can be washed to the top. The supply of rinsing fluid to the wells is metered by timing the period for which the supply valve (84) is opened. To ensure that the flow through the valve is at a uniform rate, the output of the pump (80) is smoothed by passing it through a length of flexible walled tubing (82) and an adjustable restrictor valve (91).