Commercial Varieties of Nuclear Fast Red; Their Behaviour in Staining After Autoradiography

Dye marketed as nuclear fast red by various British firms (mixtures of anthraquinones by B. D. H. and G. T. Gurr, a quinone-imine dye by E. Gurr and Kodak) were investigated as nuclear stains particularly in autoradiography where the uptake of haematoxylin hindered visualization of the grains; in this case the uptake of S35 by the epiphyseal plate of the tibiae of mice. A 0.1% solution of the anthraquinone dye CI 60760 (Nuclear fast red; G. T. Gurr) in saturated potassium aluminium sulphate gave a good nuclear stain and was used in the staining sequence: Alcian blue—nuclear fast red—tartrazine. These dyes barely coloured the emulsions used (both stripping film and gel-form emulsion) so that visualization of the silver grains and histological detail were good. The strains were applied after development and other processing of the emulsion was complete.