Biocompatibility of Sessile Drops as Chambers for Cell Culture

Biological assays are often performed in parallel in multi-well plates, e.g., 96-well plates. Arrays of sessile drops in a standard tissue-culture Petri dish, overlaid with an immiscible liquid to prevent evaporation, have been employed as a platform to perform such assays in even smaller volumes (microliters or less) and increase throughput. To apply this method for assays involving cell culture, it is essential to ensure the system is biocompatible. We observed that human embryonic kidney (HEK) cells attach and proliferate at a lower rate when cultured in drops with high surface-to-volume ratio compared to conventional cultures. We found that increasing the serum concentration in drops or pre-exposing footprints of drops to medium plus serum improves cell adhesion.