Tissue clearing approaches started to revolutionize standard histology by allowing to image intact organs and organisms. To upscale the size and quality of volumetric imaging, we developed 3DISCO and recently its imporved version ultimate (u)DUSCO. uDISCO clearing can achieve sub-cellular resolution imaging of enture organs and orgnaisms including adult rodent bodies without tissue sectioning. We used uDISCO to image neuronal connections and vasculature from head to toe over 7 centimeters and do unbiased screening of transplanted stem cells in the entire body of adult mice at single cell resolution. uDISCO is compatible with diverse labeling methods and archival human tissue. DISCO clearing is fast (can be completed within a few hours), versatile (applicable to various tissues including the spinal cord, brain, lung, mammary glands, immune organs, stem cells and tumors), and can be executed using various microscopy techniques, including widefield epifluorescence, confocal, 2-photon and light-sheet microscopy.