Fuchsin-Borax working solution for Araldite consists of 500 ml of 0.25% basic fuchsin solution (CAS No.: ) and 500 ml of 0.25% sodium tetraborate/borax solution (CAS No.: ). It is used in medical diagnostics, histology and scientific laboratories. The solution is particularly suitable for staining sectional preparations from Araldite embedding media.

Basich fuchsin (C.I. 42510) is a synthetic dye belonging to the triphenylmethane dye group and has the chemical formula C_20H_19N_3-HCl. Sodium tetraborate, also known as borax, has the chemical formula Na_2B_4O_7-10H_2O and serves as a buffer in this solution.

The chemical reaction between basic fuchsin and borax results in the formation of a stable dye complex that is able to selectively interact with the tissue structures of the specimen. The staining is based on the electrostatic interaction between the positively charged dye molecules and the negatively charged tissue components, especially the acidic polysaccharides and nucleic acids.