ABSTRACT
Lysosomes were discovered in 1959 through a series of brilliant investigations by de Duve and coworkers (14,15). These cytoplasmic organelles, ubiquitous in distribution in living cells, show great diversity in form, origin, and function. Varying in diameter from approximately 0.25 to 0.5 mm, they are easily recognizable by their characteristic biochemical and morphological properties. Lysosomes are a component of a system of intracellular organelles known as the endosomal-lysosomal system (16). This system consists of three parts: the early endosome, the late endosome and the lysosome (primary and secondary) which together are responsible for trafficking and digestion of endocytosed molecules and also for recycling and sorting of materials within the cellular matrix (51). Lysosomes are the sole site of digestive activity in living cells.
