a stain for intact epoxy sections; semi-thick sections of plastic-embedded tissues have the following structures stained blue to black: chromatin, nucleoli, basophilic cytoplasm, mitochondria, plasma and nuclear membranes, anisotropic myofibrils, mast cell granules, and elastic membranes of blood vessels; appearing pink to red are collagen fibrils, reticulum, goblet cell mucins, hyalin cartilage matrix, stereocilia, cytoplasm, and erythrocytes; fat droplets and perichondrocyte matrix are green.