Xanthylium, 9-[4-[[[5-[[(2S)-2-amino-6-[[5-[(3aS,4S,6aR)-hexahydro-2-oxo-1H-thieno[3,4-d]imidazol-4-yl]-1-oxopentyl]amino]-1-oxohexyl]amino]pentyl]amino]carbonyl]-2-carboxyphenyl]-3,6-bis(dimethylamino)-, inner salt

TMR Biocytin can be used to examine the permeability changes of blood brain barrier (BBB)^[2].
Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs)^[2].
1. Dilute 1 mg TMR Biocytin in 100 μL PBS (per mouse), and inject the solution into the tail vein.
2. 30 min after injection, anesthetize and perfuse the animals.
3. Remove spinal cords, prepare deep frozen and serial 10 μm longitudinal sections.
4. Stain nuclear counterstain using DAPI.
5. Obtaine the images of whole sections with ×10 power of objective, ×10 power of eyepiece, by using identical laser intensity, exposure times and magnification in all cohorts.
6. To set the above parameters, livers from tracer injected mice and non-injected mice were used.