Fig. 1

Immunohistochemical staining of tryptase-positive mast cells in human bronchial submucosa tissue. a Representative 20X image of positive staining using mAb AA1 for tryptase with positive staining in red with Mayer’s hematoxylin counterstain in blue from a subject exposed to FAA. b Zoom region (40X) highlighted in panel a black box. c Positive pixel count quantification of submucosa region for tryptase staining. Data are expressed as mean ± SEM. n = 10 for each experimental condition