The thermo-reversible mountant CyGEL, from Biostatus Ltd. in the UK, enables high resolution imaging of live 3D tumor spheroids cultured in low-adherence conditions and without fixation or cytospin centrifugation. A recent paper confirms that CyGEL stabilizes multicellular structures for imaging and characterization, whilst retaining cellular viability, morphology and protein expression. CyGEL is optically inert and clear, compatible with fluorescence and permits delivery of organelle-specific and viability probes. Objects can be isolated, imaged and then easily recovered for orthogonal analysis. CyGEL allows a breadth of advanced microscopic techniques for live-cell imaging of both mammalian and non-mammalian structures.