Trypan blue solution 0.4 %, for microscopy, 100 ml, plasticTrypan blue solution 0. 4 %, for microscopy, Density (D) ~1 g cm, Boiling point (bp) 100 C, Storage temp. +15 to +25 C As an anionic azo dye trypan blue binds to the cell proteins. Since it is not membrane permeable, it only stains dead cells. Directions for use It is commonly used in a 0,4 % aqueous solution to determine the vitality of cells. The solution is sterile filtered and durable for a period of two years. PDF Technical Documentation (PDF)