Fibrillin in the alveoli in lung tissue (human, adult)

Stain: imunoperoxidase staining with anti-fibrillin antibodies and diaminobenzidin reaction (frozen section). Fibrillin is one of the elastin-associated microfibrillar proteins that wraps the elastin protein core and is localized in normal lung structures such as alveolar septa and tips. The immuno-staining reveals the thread-like black fibrillin deposits. (A) are the alveolar spaces, and arrowheads point to alveolar tips (↓1), where coiled deposits can be discerned. Open capillaries are indicated by (2↓).