Fig. 1

Images and scores from PAS, dPAS and AB stained tissues sections. a Mouse liver with PAS (left) and dPAS (right) stains, bar = 48 µm. Note the abundant and widespread cytoplasmic magenta staining in the PAS, but absent in the dPAS livers. b Pig trachea with PAS and dPAS stains, bar = 85 µm. Note the ciliated cells (arrows, insets) with cytoplasmic magenta staining in PAS, but absent in PAS trachea. c Pig trachea with AB and dPAS stains, bar = 85 µm. Note that AB and dPAS techniques preferentially stain mucin in goblet cells, but lack nonspecific cytoplasmic staining of adjacent ciliated cells as seen in b. d–f Evaluation of PAS, dPAS, and AB mucin staining in the trachea. d Extent of mucin in surface epithelium (SE) normalized to serial dPAS sections (value of “1”), bars = mean ± sem. The presence of glycogen significantly increased the PAS versus dPAS staining of SE (P = 0.0078). Comparison of dPAS and AB showed no significant differences (P > 0.9999) even though the tissues still had glycogen for the AB technique. e Ordinal scores for mucin staining within SE goblet cells showed no significant differences (P = 0.125 and 0.625, respectively). f Ordinal scores for nonspecific mucin staining in ciliated cells of the SE showed increased PAS versus dPAS scores, but no difference in AB and dPAS scores (P = 0.0156 and 0.9999, respectively)