Here we describe a protocol for advanced CUCUBIC (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis). The CUCUBIC protocol enables simple and efficient organ clearing, rapid imaging by light-sheet microscopy and quantitative imaging analysis of multiple samples. The organ or body is cleared by immersion for 1-14 d, with the exact time required dependent on the sample type and the experimental purposes. A single imaging set can be completed in 30-60 min. Image processing and analysis can take <1 d, but it is dependent on the number of samples in the data set. The CUCUBIC clearing protocol can process multiple samples simultaneously. We previously used CUCUBIC to image whole-brain neural activities at single-cell resolution using Arc-dVenus transgenic (Tg) mice. CUCUBIC informatics calculated the Venus signal subtraction, comparing different brains at a whole-organ scale. These protocols provide a platform for organism-level systems biology by comprehensively detecting cells in a whole organ or body.