Fig. 1: HYdrogel Dispensing method with Robotic Automation (HYDRA) for HTS-compatible hydrogels.

a Schematic illustration of the Hydrogel Dispensing with Robotic Automation (HYDRA) method. b Photograph of the robot performing the HYDRA of fish gelatin (FG) hydrogels in a 96-well plate. A red food colorant was added for visualization purposes. c Isometric confocal z-stack (3D rendering) of an enzymatically crosslinked FG hydrogel embedding fluorescent beads and HaCaT cells seeded on top and on the side of the hydrogel. d Schematic representation of drug tests performed with nocodazole and paclitaxel. Drug dose (three concentrations of each drug color-coded as blue – low concentration, red – medium concentration, and black – high concentration) increases along columns. e Gel compatibility with standard imaging approaches in high throughput plates using HaCaT cells. (i) Time-lapse holographic imaging for long-term low phototoxicity studies and (ii) static fluorescence imaging of cells treated with nocodazole or paclitaxel drugs and imaged for 48 hours after treatment. In both cases the gels were cast on inexpensive traditional tissue culture plastic. iii) High-resolution fluorescence imaging experiments of HaCaT cell proliferation for 18 hours (high magnification, 40× silicon oil objective). The white, green, cyan, and magenta colors in (ii) and (iii) correspond to actin, tubulin, and nuclei of cells in the G1 and S/G2 phases, respectively. Scale bars: 25 μm.