This dye has been used as a counterstain in saturated aqueous potassium alum and in a counterstain solution of 0.1% (w/v) with 5% aluminum sulfate for a Prussian Blue Stain for ferric iron. It has been used as a reagent for calcium in tissue where it forms a scarlet lake.

Lakes are also formed with lead, ferric ion, copper, tin, and strontium, but not barium.1,2 The suitability of nuclear fast red as a nuclear stain in autoradiographs of knee joints of mice and rats has been reported.

Nuclear Fast Red Solution Application

Used as a red nuclear counterstain. Nuclear Fast Red solution has been used:

• In the dual-beam (FIB (focused ion beam)/SEM (scanning electron microscopy)) analysis of intracellular MNPs (magnetic nanoparticles) distribution.
• As a counterstain in LacZ tissue histological analysis, and in extracellular matrix proteoglycan staining.
• In situ hybridization.

Components Require

The following components are required to prepare 1L of Nuclear Fast Red Solution.

Component	Amount	Concentration
nuclear fast red (Kernechtrot; C.I. 60760) (mw: 357.27 g/mol)	1 g	0.0028 M
aluminum sulfate (Al2[SO4]3•18H2O) (mw: 666.43 g/mol)	50 g	0.075 M

Nuclear Fast Red Solution Preparation

1. Prepare 800 mL of distilled water in a suitable container.
2. Add 1 g of nuclear fast red (Kernechtrot; C.I. 60760) to the solution.
3. Add 50 g of aluminum sulfate (Al2[SO4]3•18H2O) to the solution.
4. Add distilled water until volume is 1 L.
5. 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.

References

• “Nuclear Fast Red Solution Preparation.” AAT Bioquest, Inc, 02 Jun. 2021, https://www.aatbio.com/resources/buffer-preparations-and-recipes/nuclear-fast-red-solution.
• https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/2/n8002pis.pdf