The presence of fine elastin fibrils within the elastin fibre observed by scanning electron microscopy.

Scanning electron microscopy of critical point dried, enzymically and chemically purified fetal and adult elastin fibres from bovine ligamentum nuchae has shown that the fibres are composed of fine elastin fibrils (110-130nm diameter). In the fetal tissue the elastin fibres were of relatively uniform thickness and did not bifurcate, but in the adult, much thicker, branching fibres were present. It would appear that, during maturation of the elastin fibre, thickening is the result of the aggregation of many fine fibrils, and bifurcations result form bundles of such fibrils crossing over from one fibre to another.