Advanced Microscopy Applications
Life Sciences

Plant cell (Modulus study)

Model: Lucent T model

Modes used – AFM – Force spectroscopy, FFOCT

The onion peel is one of the most common samples used by biology students. We use the AFM and FFOCT combination to unravel the structure and mechanical modulus. Our software reconstructs the top and bottom membranes of the cells. A blunt AFM tip is used to ‘indent’ into the surface. The cell membrane is remarkably resilient and can undergo large deformations. The FFOCT data is used not only to reconstruct the surfaces in 3d, but also obtain label free spectroscopic signatures which are then overlayed on the position map.  The interconnected filamentous cytoskeleton structure can be seen in some of the ‘FFOCT intensity’ plots. For moderate tip penetration, cell membrane repairs itself, leaving behind a signature that is seen in the ‘FFOCT spectrum’ plot.