Liu's stain

Liu's stain (劉氏染色法) is a staining technique used to stain animal cells. It is an improved staining based on Romanowsky stain, and was introduced by professor Chen-Hui Liu(劉禎輝), faculty of National Taiwan University, in 1953. The method sees a wide variety of usage in Taiwan. Comparing to other staining methods, Liu's stain is relatively fast, taking no more than 3 minutes to complete the process. In pathology, Liu's stain is primarily used to distinguish blood cells, but it can also apply on vaginal discharge, sputum, and pus as a simple stain.

Components
Liu's stain is composed of two dyes, Liu A and Liu B. Liu A is the anionic dye, contains eosin Y to stain cytoplasm as well as hemoglobin into red. Liu B, on the other hand, is the cationic dye, contains azur I and methylene azure, to stain nucleus and basophilic granules into blue. To apply the stain on a fixed smear, first add Liu A for some 45 seconds, then add Liu B for some 90 seconds. Then, wash off the excessive dye by gently flushing the back of the smear. The staining is done after the water on the smear dried up.