The Reticulin Stain is a highly specialized, expert-level test used by our pathologists to analyze your body's "scaffolding." It is most often performed on a bone marrow biopsy. This special stain highlights the 'reticulin' fiber network (connective tissue) inside the marrow. This is the definitive test for diagnosing myelofibrosis, a condition where this network becomes scarred and dense, crowding out healthy blood-producing cells. This test is critical for your hematologist to get a precise, structural diagnosis and create the right treatment plan.