The Sternheimer-Malbin (SM) stain is a commonly used supravital stain containing crystal-violet and safranin. WBC's, epithelial cells, and casts stain well with SM stain. Sedi-Strain (Clay Adams, Sparks, MD) and Kova stain (ICL Scientific) are among those commercially available. Nuclei and cytoplasm of various cells can be stained with a 0.5% solution of toluidine blue.