Evaluation of a liquid dispenser for assay development and enzymology in 1536 well format

While developments in liquid dispensers have made the use of 1536 well plates for high throughput screen (HTS) standard, there is still a gap in dispenser technology for performing matrix experiments with several components. Experiments such as those performed during assay development and enzymological studies are therefore still performed by manual pipetting in lower density plates. We have evaluated a new dispenser, the Certus liquid dispenser (Gyger Fluidics GmbH, Switzerland), that is capable of flexible dispensing in 1536 well format, with a dead volume of less than 200 µl. Taking advantage of the precision of the dispenser for volumes down to 50 nl, we have create concentration gradients on plates by dispensing different volumes of reagent and then backfilling with buffer. Using this method and the flexibility of the dispenser software, we have performed several multidimensional experiments varying 2 – 3 components, including an assay development for an HTS, a mode of inhibition study, and a co-factor optimization, where we determined 32 KM values. Overall, the flexibility of plate layout for multiple components, the accuracy to dispense volumes ranging 2 log orders, and minimal reagent usage, makes this dispenser enabling for complex biochemical experiments