Proteinaceous material from potsherds and associated soils

Amino acid and protein analyses of a range of archaeological potsherds and associated burial soils were performed by direct hydrolysis of powdered soils and potsherds samples, followed by high performance ion exchange chromatography. Detection of the eluting amino acids was by post-column derivatization, using o-phthalaldehyde and fluorescence monitoring. Microgram amounts of hydrolysed amino acids were detected in all the potsherds and soils analysed; free amino acids in both potsherd and soils were often below delectable limits (sherds recovered from the same archaeological context). The protein analyses involved extraction of powdered soil and potsherd samples with urea buffer,followed by polyacrylamide gel electrophoresis and protein staining. High sensitivity detection of the proteins used gold staining, following electrotransfer on to nitrocellulose. No obvious protein bands of molecular weight >10 kDa were detected in any of the potsherd samples that were studied. In general the amino acid and protein compositions of the individual potsherds were not sufficiently characteristic to suggest that HPLC ''fingerprinting'' of amino acids would significantly contribute to palaeodietary analysis or vessel use. Two potsherds, however, exhibited evidence of gelatin/collagen amino acid patterns. The presence of small amounts of gelatin were confirmed by the digestion of a >10 kDa protein extracted by bacterial collagenase. (C) 1996 Academic Press Limited