BACKGROUND: There are many methods for myelin staining, mordant, or oil-soluble dye or the special reaction of osmic acid with lipoid is used according to different principles. The commonly used methods are classic Well staining, classic lithium carbonate-haematine staining, fast green staining, silver staining, etc. Luxol Fast Blue can brightly stain myelin sheath, and has certain specificity. The background can be very clean if there is proper differentiation, whereas Luxol Fast Blue is cheap and convenient to operate, thus it is an ideal staining reagent for routine myelin sheath. OBJECTIVE: To show the corticospinal tract of normal adult rats with Luxol Fast Blue staining method. DESIGN: A repetitive measurement design. SETTINGS: Institute of Nuerobiology, Nantong University; Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University. MATERIALS: Six healthy adult male SD rats of clean degree, weighing averagely 300 g, were provided by the experimental animal center of Nantong University. 1 g/L Luxol Fast Blue solution was provided by Sigma Company; Leica CM1900 cryostat microtome by Leica Company; Leica DMR microscope by Leica Company. METHODS: The experiment was carried out in the Staff Room of Human Anatomy, Nantong University in May 2005. The rats were given intraperitoneal injection of combined anesthetic (2 mL/kg), then the chest was open for perfusing saline and phosphate buffer containing formamint via heart. Brain and spinal cord were removed after 1 hour then fixed, then changed to phosphate buffer (pH 7.4) containing 300 g/L saccharu at 4 ℃, and stayed overnight, tissue blocks at pyramid, decussation of pyramid and cervical, thoracic, lumbar and sacral segments of spinal cord were removed to prepare continuous horizontal frozen sections (30 μm) after sedimentation, the sections were dried at room temperature. The corticospinal tract of normal adult rats were shown with Luxol Fast Blue staining method, and observed under Leica DMR microscope. MAIN OUTCOME MEASURES: Positive fibers in Luxol Fast Blue staining. RESULTS: After the Luxol Fast Blue staining, the labeled myelinated nerve fibers were bright blue. They located in the pyramid, decussation of pyramid and the ventral part of posterior funiculus in cervical, thoracic, lumbar and sacral segments of spinal cord. CONCLUSION: Luxol Fast Blue staining method may manifest the distribution of corticospinal tract with clear distinct in adult rats. BACKGROUND: There are many methods for myelin staining, mordant, or oil-soluble dye or the special reaction of osmic acid with lipoid is used according to different principles. The commonly used methods are classic Well staining, classic lithium carbonate-haematine staining, fast green staining, silver staining, etc. Luxol Fast Blue can brightly stain myelin sheath, and has certain specificity. The background can be very clean if there is proper differentiation, while Luxol Fast Blue is cheap and convenient to operate, thus it is an ideal OBJECTIVE: To show the corticospinal tract of normal adult rats with Luxol Fast Blue staining method. DESIGN: A repetitive measurement design. SETTINGS: Institute of Nuerobiology, Nantong University; Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University. MATERIALS: Six healthy adult male SD rats of clean degree, weighing averagely 300 g, were provided by the experimental animal c enter of Nantong University. 1 g / L Luxol Fast Blue solution was provided by Sigma Company; Leica CM1900 cryostat microtome by Leica Company; Leica DMR microscope by Leica Company. METHODS: The experiment was carried out in the Staff Room of Human Anatomy, Nantong University in May 2005. The rats were given intraperitoneal injection of combined anesthetic (2 mL / kg), then the chest was opened for perfusing saline and phosphate buffer containing formamint via heart. Brain and spinal cord were removed after 1 hour then fixed, then changed to phosphate buffer (pH 7.4) containing 300 g / L saccharu at 4 ° C and stayed overnight, tissue blocks at pyramid, decussation of pyramid and cervical, thoracic, lumbar and sacral segments of spinal cord were removed to prepare continuous horizontal frozen sections (30 μm) after sedimentation, the sections were dried at room temperature. The corticospinal tract of normal adult rats were shown with Luxol Fast Blue staining method, and observed under Leica D MRmicroscope. MAIN OUTCOME MEASURES: Positive fibers in Luxol Fast Blue staining. RESULTS: After the Luxol Fast Blue staining, the labeled myelinated nerve fibers were bright blue. They located in the pyramid, decussation of pyramid and the ventral part of posterior funiculus in cervical , thoracic, lumbar and sacral segments of spinal cord. CONCLUSION: Luxol Fast Blue staining method may manifest the distribution of corticospinal tract with clear distinct in adult rats.