The article describes three heavy metal stains used for staining tissue sections for electron microscopy: lead hydroxide, barium hydroxide, and alkalized lead acetate. Lead hydroxide selectively stains two types of particles in liver cells: those associated with the endoplasmic reticulum and containing RNA, and other larger particles. Barium hydroxide emphasizes certain bodies within vesicles of the Golgi region of hepatic cells. Alkalized lead acetate is a general stain. The methods involve fixing liver tissue, embedding in n-butyl methacrylate, and staining sections with the heavy metal solutions. Lead acetate is used as a saturated solution, which can be alkalized for more intense staining. Barium hydroxide is used as a saturated solution, which may become cloudy due to barium carbonate formation but can be clarified by standing. Lead hydroxide is prepared by dissolving lead acetate and adding sodium hydroxide, followed by centrifugation and resuspension. The results show that lead acetate stains various cellular components, including membranes, nuclei, RNA-containing particles, and collagen. Barium hydroxide stains certain structures in the Golgi region and lipide inclusions. Lead hydroxide stains irregularly shaped particles in liver cells, possibly representing glycogen deposits, and stains RNA-containing particles, though less uniformly than lead acetate. The discussion highlights the affinity of lead and barium hydroxides for specific cytoplasmic structures. Lead hydroxide is noted for its strong staining of RNA-containing particles and its high density. Barium hydroxide is effective for certain Golgi structures. The study emphasizes the importance of staining time and the potential for differential extraction and stabilization of tissue components during staining. Lead hydroxide is considered the most useful of the three due to its broad applicability and high density. The article also notes the toxicity of lead and the need for caution in handling dried salts.The article describes three heavy metal stains used for staining tissue sections for electron microscopy: lead hydroxide, barium hydroxide, and alkalized lead acetate. Lead hydroxide selectively stains two types of particles in liver cells: those associated with the endoplasmic reticulum and containing RNA, and other larger particles. Barium hydroxide emphasizes certain bodies within vesicles of the Golgi region of hepatic cells. Alkalized lead acetate is a general stain. The methods involve fixing liver tissue, embedding in n-butyl methacrylate, and staining sections with the heavy metal solutions. Lead acetate is used as a saturated solution, which can be alkalized for more intense staining. Barium hydroxide is used as a saturated solution, which may become cloudy due to barium carbonate formation but can be clarified by standing. Lead hydroxide is prepared by dissolving lead acetate and adding sodium hydroxide, followed by centrifugation and resuspension. The results show that lead acetate stains various cellular components, including membranes, nuclei, RNA-containing particles, and collagen. Barium hydroxide stains certain structures in the Golgi region and lipide inclusions. Lead hydroxide stains irregularly shaped particles in liver cells, possibly representing glycogen deposits, and stains RNA-containing particles, though less uniformly than lead acetate. The discussion highlights the affinity of lead and barium hydroxides for specific cytoplasmic structures. Lead hydroxide is noted for its strong staining of RNA-containing particles and its high density. Barium hydroxide is effective for certain Golgi structures. The study emphasizes the importance of staining time and the potential for differential extraction and stabilization of tissue components during staining. Lead hydroxide is considered the most useful of the three due to its broad applicability and high density. The article also notes the toxicity of lead and the need for caution in handling dried salts.