The main challenge faced by electron microscopists is to find the « good » cell at the proper location. By using patterns we can control the size, shape and position of the cells on substrates compatible with EM observations. We are able to make patterns on different substrates such as microscopy grids for Cryo-EM, glass slides for MET and aclar for SEM. Coupled with electron microscopy and patterns would allow us to study in more detail the cell-cell and ligand-receptor interactions. But also to be able to correctly orientate growth cones or synapses in order to increase the yield of the experiments.