The Removal of Protein from Mineral Surfaces: Implications for Residue Analysis of Archaeological Materials

Although there has been great interest and controversy concerning the detection of proteins in archaeological residues, very few studies have considered the effect of different extraction methods. Using well-defined control materials, this study compares the extraction efficiency of a number of different extraction reagents. Immunological and spectrophotometric assays are used to assess the amount of protein removed by each extraction method and the effectiveness is reported with reference to previous work. None of the previously reported methods were found to be effective at removing the protein from the mineral surface. We conclude that proteins are very strongly bound to the surface probably via short-range bonds. Although this may be encouraging for the long-term preservation of proteins in this context, extraction methods will have to be re-evaluated in order to achieve efficient recovery.