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.