“…Blood flow is important in basic research as well as in pathology such as stroke, and the reconstruction of the vasculature in three-dimensions (3D) is a valuable investigative tool. Within the last decade several tissue-clearing techniques, have been developed, which make large samples transparent and enables microscopy of the 3D structures within intact organs (Ertürk et al, 2012;Chung et al, 2013;Yang et al, 2014;Epp et al, 2015;Zheng and Rinaman, 2016;Kolesová et al, 2016;Neckel et al, 2016;Liu et al, 2017;Carrillo et al, 2018;Qi et al, 2019;Cai et al, 2019). One of the early, and still, powerful methods is CLARITY (Clear Lipidexchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel) (Gradinaru et al, 2018;Jensen and Berg, 2017), which utilizes an acrylamide-hydrogel to keep proteins bonded in a skeleton structure and the removal of lipids, which are the primary cause of light-scattering in tissues, by using a detergent leaving the tissue transparent (Chung et al, 2013;Tomer et al, 2014).…”