Cell injection is one of the core methods to introduce non-permeable molecules into cells. It allows direct access to the two main intracellular compartments, the nucleus and cytoplasm. The video above shows dye (for visualization) being injected into living human dermal fibroblast cells. Cell injection is used in conjunction with AFM and other biophysical imaging techniques to connect cell elasticity to overall cell health. For instance, fluorescent nanomaterials for particle tracking or for therapeutic delivery can be injected, followed by imaging and then imaging can be analyzed for determining intracellular trafficking, dispersion and transport within cellular compartments. This can be coupled with mechanical measurements which indicate changes in cells occurring as a result of injected materials exerting a biological effect.