text: Microcrystallization (or microcrystal test) is a method for identifying lichen metabolites that was predominantly used before the advent of more advanced techniques such as thin-layer chromatography and high-performance liquid chromatography. Developed primarily by Yasuhiko Asahina, this approach relies on the formation of distinctive crystals from lichen extracts. Although now superseded by modern analytical methods, microcrystallization still holds importance for compound purification and analysis using X-ray crystallography.