Reticular fibers are abundant in lymphoid organs (lymph nodes, spleen), bone marrow and liver.
Reticular fibers are composed of thin and delicately woven strands of type III collagen. They are not visible with hematoxylin & eosin (H&E), but are specifically stained by silver. This renders them black and makes them easily distinguishable from type I collagen fibers that are stained red/brown.
Lymph nodes are examples of tissues with a reticular framework that supports its cellular constituents.
Surrounding the lymph node is a capsule of collagen fibers (type I collagen) stained red.
The outer portion of the lymph node contains aggregations of lymphocytes organized in nodules. Reticular fibers (type III collagen) stained black surround