Organelles are generally considered to be microstructures or micro-organs with specific morphology and functions dispersed within the cytoplasm. They are typically found in the cytoplasm of both eukaryotic and prokaryotic cells. In eukaryotic cells, organelles are often enclosed by phospholipid bilayers. Similar to the organs in the body, organelles are specialized functional units that carry out essential cellular operations. Their functions are broad, ranging from energy production for the cell to regulating cell growth and reproduction. Organelle markers are important research tools in the study of cell structure and function. Through immunofluorescence techniques, the distribution and subcellular localization of target proteins can be assessed. In immunoblotting experiments with organelle extracts, they serve as positive controls to verify whether the organelle extraction was successful. Transmission electron microscopy can be used to observe the morphological structure of organelles.