Nuclear fast red solution
0.2 g nuclear fast red (Kernechtrot; C.I. 60760)
10 g aluminum sulfate (Al2[SO4]3•18H2O)
200 mL H2O
Combine above reagents and heat with stirring until nearly boiling, then leave overnight to cool. There is a substantial residue of insoluble material, which must be removed by decanting and filtering. The solution keeps for ~1 yr; it may need to be filtered before each use.
