Used in histology to selectively stain elastic fibers in tissue sections, particularly in skin, blood vessels, and lung tissues. The stain helps visualize the structure and integrity of elastic fibers under light microscopy, making it valuable in diagnosing conditions such as emphysema, arterial hypertension, and connective tissue disorders. It is commonly applied in research and pathology to assess changes in elastic fiber networks due to aging, disease, or environmental damage. The aldehyde-fuchsin method offers high specificity and contrast, especially when evaluating fragmented or reduced elastic fibers in diseased tissues.