 These overlap and gap regions are retained as microfibrils assemble into fibrils, and are thus viewable using electron microscopy.The triple helical tropocollagens in the microfibrils are arranged in a quasihexagonal packing pattern.There is some covalent crosslinking within the triple helices, and a variable amount of covalent crosslinking between tropocollagen helices forming well organized aggregates (such as fibrils).