The use of the fluorescent probe 8‐anilino‐1‐naphthalene sulphonic acid (ANS) as a histochemical stain in plant tissues

The fluorescent probe 8‐anilino‐l‐naphthalene sulphonic acid (ANS) has been evaluated as a histochemical stain for plant tissues. The wide specificity of the compound for hydrophobic binding sites limits its analytical use, but renders it of considerable value as a general fluorescent stain for use in epi‐illumination fluorescence microscopy. Used in this way it is analogous to the light‐microscope stain toluidine blue. ANS has also been found to be a sensitive vascular tracer.