Although the function of many of the subnuclear bodies remains elusive, they are indeed true nuclear structures. They are seen both by light and electron microscopy and can be studied in living cells through the use of fluorescent tags. They are known to contain complexes of proteins with or without RNA. Like nucleoli, they are not surrounded by a membrane. They often move through interchromatin channels and are thought to represent dynamic complexes that may form and re-form with each other and other nuclear components to process and transport nuclear components.