SEM characterization of blood stains on stone tools

Policarp Hortolà

The Microscope, vol. 40 (2), pp. 111-113, 1992 [Editor's ‘Errata’ published in vol. 40 (3), p. vi, 1992]

KEYWORDS: Red blood cells, bloodstains, scanning electron microscopy, archeology

ABSTRACT

Mammalian red blood cells (RBC) in bloodstains have been previously detected by light microscopy on stone tools circa 100,000 years old. To observe and characterize the bloodstain-original RBC, a modern replica of ancient blood residues was examined by scanning electron microscopy (SEM). To simulate a Stone Age process a collared peccary (Tayassu tajacu) cadaver was skinned using a paleolithic-like white chert knife, which was then smeared with blood plus serous liquid. After drying in the open air for one week, the tool was stored at unsterile and fluctuant room conditions. After six months, a detached fragment of the bloodstain  on a SEM stub was coated with gold and examined at an accelerating voltage of 15 kV using a Cambridge STEREOSCAN 120 scanning electron microscope. Results reveal protuberant moon-like shapes which are interpreted to be characteristic of RBC.