GRAM STAIN
1. Crystal violet (1o stain). Colors cytoplasm of all cells
2. Iodine- used as “mordant” binds to dye and helps resist decolorization
3. Decolorizing agent (alcohol)- G+ cells are not decolorized, G- cells become colorless (decrease pores and trap dye).
4. Counter stain- Safranin (red)