Nowadays, microphysiological systems (MPS) recapitulate native microenvironments in vitro with high fidelity, to imitate physiological or pathological architectures and processes at multiple scales in space and time. Compatible with traditional biological analyses and microscopy (real-time or end-point measurements), they enable the precise study of tissue-like constructs and facilitate mechanistic studies. It has become possible to recreate the organization and functions of complete organs inside microfluidic systems called organ-on-chips (OoC), where the crucial role on tissue homeostasis of factors like multicellularity, mechanics, morphogens and flow-mediated cell-cell exchange has been demonstrated. A particular emphasis has been put on the importance of the interactions between epithelial cells and endothelial cells in all OoCs. For any model to be developed, it is critical to correctly design and fabricate MPS and OoCs in agreement with application-dependent specifications, for biology research and in particular, where microscopy tools are used. In spite of their advantages, developing these techniques may seem overwhelming for non experts and limits their broad adoption by biologists. In this workshop, we will present how to readily fabricate one of the most important and widely used device: a 2-channel microfluidic chip where an epithelial and an endothelial channel are separated by a porous membrane. We will provide a clear methodology for beginners to offer a solid background to start working in their own lab. Micromolds of the 2-channel chip will be used to replicate structures in PDMS and assembled into a functional microfluidic chip where channel-to-channel diffusion tests will be performed using fluorescent dyes with wide-field microscopy. Several critical tips/tricks will be provided at each stage (fabrication, interconection, flow) to help reproduce the device successfully and test it under their own microscope environment (widefield or confocal).