Technical aspects of the Haematoxylin--Basic Fuchsin--picric acid (HBFP) stain applied to skeletal muscle.

The Haematoxylin-Basic Fuchsin-picric acid (HBFP) stain, a new non-enzymatic histochemical technique described previously to detect early myocardial ischemia, was applied to skeletal muscle. Several factors were found which have an important effect on HBFP positivity including ageing in room air of unstained tissue sections, and the precise timing of the differentiation step of this stain. Using carefully standardized techniques, repeatable staining was obtained and a high level of interobserver consistency in the interpretation of staining results was achieved. Although the technical requirements of this new stain are rigorous, it offers promise and deserves further evaluation in the study of skeletal as well as cardiac muscle disorders. The histological advantages include vivid contrasts and the ability to use the stain on formalin-fixed paraffin-embedded muscle tissue.