Alcian Blue and Pyronine Y histochemical stains of paraffin embedded sections provide multi‐parameter morphologic assessment in experimental models of pulmonary disease

Pulmonary researchers often assess morphologic parameters to determine disease progression or response to novel therapeutics. Detection of morphologic parameters by special stains is essential for assessment. We show novel application of Alcian Blue and Pyronine Y histochemical stains in experimental models of lung disease to provide multi‐parameter tissue assessment. The Alcian Blue provided intrinsic counterstaining through pale blue staining of nuclei. Acidic mucins of airway epithelia or submucosal glands were stained deep blue (sialylated mucins), red (sulfated mucins), or purple (sialylated/sulfated mucins). Elastic fibers stained red within the walls of pulmonary arteries, connecting airways, alveolar septa and subpleural space. Mast cells were readily detected in select species by red granular cytoplasmic staining. Mucin alterations were readily detected in a respiratory syncytial virus hypersensitivity model and elastin loss in a model of bronchiectasis. Experimental models of respiratory disease which had representative staining included: inbred mice, rat, ferret, cat, dog, sheep and pig. This histochemical stain assesses multiple morphologic parameters often required by pulmonary investigators, is cost effective, simple to perform, and reduces the needs for repeated serial sectioning. This work is supported by the Department of Pathology (University of Iowa) and the NIH.