A bulk dispenser can be a good option for many applications, such as dispensing buffer solutions or media for cell cultures. One method of producing microlitre-sized droplets is to use fast-switching solenoid valves. To dispense the fluid, these valves can be supplied via a fluid line, for instance from a pressurised reservoir. The image below shows an example of a simple system:
Right now, the majority of automated liquid handling systems work with volumes in the microlitre to millilitre range. A current trend that can be observed is the increasing miniaturisation of assays; this enables laboratories to reduce reagent and sample costs while increasing throughput. An intelligent combination of pipetting and bulk dispensing can help optimise the automation of liquid handling processes.