G protein-coupled receptors (GPCRs) are involved in virtually all physiological processes and as such are important targets for drug development. The PAC1R has been implicated in disease, including chronic stress disorders, anxiety and post-traumatic stress disorder, as well as migraine. Despite this there are currently no drugs on the market targeting PAC1R. Since 2017 cryogenic electron-microscopy (cryo-EM) has become an established tool for studying GPCR structures (Liang et al., 2017). Full-length cryo-EM structures of the PAC1R have been determined, though they are currently limited to active-state Gs G protein-bound complexes. There are no structures of PAC1R in the apo/inactive states, which means only a limited subset of PAC1R conformations have been structurally visualised. To address this gap in structures of intermediate states, we have undertaken various approaches to optimise sample preparation of apo/inactive state PAC1Rs. These include (i) the co-expression of a mutant G11 construct with PAC1R in insect cells to boost receptor expression and (ii) varying concentrations of salts in buffers during purification to assist G protein dissociation from PAC1R. Adjustment of glow discharge time and blotting conditions of grids has also been explored to identify conditions where particles are distributed within thin vitreous ice that is suitable for imaging of small membrane proteins like PAC1R. This work has enabled preliminary 2D classifications of PAC1R in the apo state using a 200 kV Glacios microscope with a Falcon 4 camera, demonstrating the ability of such equipment to image small and dynamic membrane proteins. However, further optimisation or stabilisation of the receptor is required to attain a high resolution 3D map. Achieving such 3D structure for the apo and ligand-bound PAC1R will provide insight into differences between active and inactive states. Ultimately, this will provide insights into PAC1R signalling and aid drug development efforts targeting this receptor.