Trypan blue

Description

Trypan blue is an azo dye, extensively used for assessment of viability of cells. It works on the principle of cell permeability dependent dye exclusion. Normal cells or those that are in the early phase of apoptosis have intact plasma membranes and thus exclude the dye whereas, dead cells or those that are in late phase of apoptosis with lysed cell membranes are permeable to the dye. Thus, viable cells appear colourless and non-viable cells appear blue.