Differentiating cardiac elastin, collagen and microfibrils with NaOH at the ultrastructural level

NaOH solutions extract elastin and collagen from epoxy-embedded thin sections containing rat cardiac connective tissue. Extraction results in a reverse staining effect of elastin and collagen ultrastructure. Microfibril contrast is enhanced by NaOH treatment. This phenomenon finds application in the possibility of differentiating elastin, collagen, and microfibrils at the ultrastructural level.