High resolution 3D microscopy in combination with tissue clearing techniques such as CLARITY, iDISCO, CUBIC is a rapidly growing area of biomedical research. It also has high potential to replace traditional 2D histology to become a method of choice for the analysis of tissue biopsy samples used in diagnosis of cancer and other diseases. However, currently there is a limited availability of contrast agents that can label organs, biological tissues, and cells in a live animal and are compatible with these techniques.