Real-Time Cell Adhesion and Proliferation Kinetics

The growth, proliferation and adhesion kinetics of Vero cells were determined using RTCA technology (ACEA Biosciences, San Diego, CA, USA) and we followed their protocol (AbuBakar et al., 2014[2 (link)]; Kho et al., 2015[5 (link)]). Briefly, 50 μl of EMEM supplemented with 10 % FBS (cell culture medium) was placed in each well of the E-plate 96 (gold-microelectrode array integrated E-plate; ACEA Biosciences, San Diego, CA USA). E-plate 96 was then connected to the system to obtain background impedance readings. This was to ensure that all wells of E-plate 96 and the connections were in good condition so as to avoid compromising the interpretation of the results. Serial dilutions of 2.0 × 10 ⁴, 1.8 × 10⁴ and 1.5 × 10⁴ cells in 50 μl were prepared, with four replicates for each of the concentrations. These serial dilutions of cell suspensions were then added to the wells containing 50 μl of culture medium. The E-plates were incubated at room temperature for 30 min in a laminar flow cabinet and then placed on the RTCA SP Station located in an incubator at 37 °C for continuous impedance recording. CI values as measured by continuous impedance recordings every 2 min reflected the cellular activities.