Histochemical reactions showing the presence of nucleic acids, protein, carbohydrates and lipids in mucus gland, A. Section stained with FR showing DNA in nuclei of epithelial cells (arrow), B. Section stained with TB showing RNA in nuclei of epithelial cells (arrow), C. Section stained with Hg-BPB showing protein secretion in epithelial cells and lumen (arrow), D. Section stained with PAS showing carbohydrate secretion in epithelial cells and lumen (arrow), E. Section stained with SBB showing lipid secretion in epithelial cells in newly emerged drone (arrow), F. Section stained with SBB showing lipid secretion in epithelial cells and lumen in 3-day old drone (arrow).