Persistence of bone collagen cross-links in skeletons of the Nuraghi population living in Sardinia 1500-1200 BC

Bone collagen has a specific molecular ultrastructure which can be proved b y birefringence. This protein, forming the main organic component of bone t issue, is known to survive millennia in paleontological bones and teeth. Bi refringence of bone collagen obtained from the skeletons of the Nuraghi pop ulation living in Sardinia c-ca 1500 years B.C, was found previously by the use of polarizing microscopy [1]. In this paper, using high pressure liqui d chromatography (HPLC) techniques, we show the existence of bone collagen cross-links preserved in Nuraghi skeletons after more than 3000 years.