Figure 1 : Micropillar induced nuclear deformations (MIND) approach to cancer cell identification.

From: A high throughput approach for analysis of cell nuclear deformability at single cell level

Figure 1

(a) Micropatterned surfaces were produced using photolithography, and then solvent casting. Cells were seeded and incubated, followed by fixation and fluorescent tagging of DNA, and imaged by a fluorescence microscope. Micrographs were analysed using a custom made algorithm. (b) When cultured on micropatterned surfaces, non-deformable (b1) and deformable (b2) cells responded to surface topography differently. Nucleus of a non-deformable cell when observed from above, was round or oval (top view) and from side (cross section) a thick portion of the nuclear material sat on top of the pillar. Nucleus of a deformable cell completely flowed into the gaps between the pillars, undergoing extensive deformations (cross section) and no nuclear compartment could be observed from the top of a pillar (top view). (c) We manufactured a micropillar array with 9 fields. Each field was named based on the dimensions of the pillars (P) and interpillar spacings/gaps (G) it was decorated with. For example, a surface with 8 × 8 μm2 pillars and 4 μm gaps was named P8G4. (d) On the SEM micrographs of the Saos-2 human osteosarcoma cells, asterix show the nuclei and chevrons show the stress fibres formed. The cell body on the micropatterned substrate was located on top of 4 adjacent pillars while the nuclear envelope is seen in the centre. Confocal images of Saos-2 cells on smooth and on P8G4 micropatterned surface are also presented to support the SEM observations (Stains: Red: Actin cytoskeleton/Alexa532 Phalloidin; Green: Nucleus/DRAQ-5) (scale bar 25 μm). Cell nuclei filling the gaps between the 4 pillars were observed showing that most of the nuclear material conforms to the shape of the gap.