Mike Benway, Larry Simonson and John Ung
Caliper Life Sciences Inc, Applications Laboratory, Hopkinton, Massachusetts, USA
"Assay-Ready" plates prepared from compound or library stock plates in real time greatly accelerates the High Throughput Screening (HTS) process. The ability to transfer and dilute 0.5μL volumes is a prerequisite for this function. Here we present preliminary data on 0.5μL dry dispensing using the Caliper Life Sciences Sciclone Advanced Liquid Handler (ALH) Workstation, configured with a Low Volume Head and 384/1536 Fixed-Cannula Array.
Materials and Methods
All testing was performed using a Sciclone ALH with a Low Volume Dispensing Head, and a Bulk Reagent Dispenser (Caliper Life Sciences). Absorbance was measured at 450nm using a Wallac Victor2 1420 Multilabel Counter (PerkinElmer).
Tartrazine was obtained from Sigma Chemical Company, Catalogue number T-0388. A stock dispensing solution was prepared by dissolving 2.8g of tartrazine into 1L of DMSO. The stock solution was prepared for dispensing volumes of 0.5μL. Deionized water (DI) was used as a diluent after dispensing into the dry plate.
Dispense accuracy is determined before measuring dry dispense precision. A calibration is performed to determine the volume dispensed. For the calibration, 50μL of deionized water is pipetted in to a 384 Well Flat Bottom, Untreated Polystyrene Assay Plates (COSTAR, Catalogue # 3702). Next, 0.5μL of the tartrazine solution is manually injected into each of 20 wells, successively, from a filled 10μL Hamilton micro syringe. The wells are manually mixed by multiple aspirate- dispense cycles using a 50μL hand pip