Abstract

Sessile Drops on a Petri Dish for Biocompatible Cell-based Assays

Aishah Prastowo, DPhil/Postgraduate Researcher, University of Oxford

Encapsulating cells in two-dimensional sessile drop arrays have been used in microfluidics for long-term response observation, for example to screen drugs. A simple technique for creating drop arrays on a standard tissue-culture-treated polystyrene (TCT-PS) petri dish or multi-well plate widely used in biology labs without further surface modification was recently developed. Sub-microliter drops are deposited to the surface using Teflon tube and programmed syringe pump and then covered with fluorocarbon to prevent evaporation. These drops maintain their contact line on the hydrophilic surface forming independent micro reaction chambers. However, we observed that culturing adherent type cells as it is in sub-microliter volumes is sub-optimal, hypothetically due to the high surface-to-volume ratio. Here, we develop strategies to ensure the biocompatibility of the system for performing assays using adherent-type human cells (i.e. cells need to grow and respond in a comparable manner to conventional assays) by modelling the adsorption of serum in the cell media at the fluorocarbon (liquid/liquid) and TCT-PS (liquid/solid) interfaces.