Reticular fiber (Reticular fiber) is a kind of fiber within the reticular connective tissue, produced by the reticular cells, the diameter is mostly in 0.2 ~ 1.0 μm, with toughness but no elasticity, there are many methods of staining of reticular fibers, but the staining principle is basically the same, most of them use ammonia-silver immersion method.

Reticular fiber staining solution (Gordon-Sweets method) is mainly oxidized, bleached, mordant, silver immersion, reduction, re-staining and other steps, commonly used to identify the nature and origin of the tumor, cancer and sarcoma, lymphosarcoma and reticulocyte sarcoma, hemangioendothelioma and hemangioepithelial tumors, bone Ewing's tumor and bone reticulocyte sarcoma, meningiomas and astrocytomas, malignant neural sheath tumors and early invasive carcinomas, and so on.