Gram's Crystal Violet is used for Gram's staining. In practice, a smear of bacterial cells is stained with crystal violet, then treated with an iodine containing mordant to increase the binding of primary stain. A decolourizing solution is used to remove the crystal violet from cells which bind it weakly and then the counterstain with safranin.

Negative staining method permits visualization of the usually transparent and unstainable capsule of many organisms, most importantly Cryptococcus neoformans. Nigrosin consists of a suspension of fine particles of carbon. These form a dark background.

Standard technique for staining reticulocytes is the new methylene blue staining. New methylene blue stains intracellular RNA blue in colour against pink stained RBCs. Depending on the stage of the reticulocyte the blue colour may be distributed in a general pattern(early reticulocytes) or punctate pattern(late reticulocyte). Cells with clear, blue cytoplasmic granules which can be seen without fine focusing are to be regarded as reticulocytes of maturation stage IV. From visual examination of a peripheral blood film so stained, the number of reticulocytes among 1000 reticulocytes is found and expressed as a percentage. This is termed the reticulocyte count. TCL115 is a reticulocyte staining solution formulated to contain new methylene blue for staining reticulocyte in blood smear.