Determination of Peach Gum in Ancient Chinese Paintings by Biotin–Streptavidin-Enzyme-Linked Immunosorbent Assay

Peach gum was the most common and widely used exudate gum in ancient China. In this study, polyclonal antibodies to peach gum were prepared using the protein of peach gum as the antigen. The polyclonal antibodies were used to identify peach gum with high sensitivity and specificity by biotin–streptavidin-enzyme-linked immunosorbent assay (BA-ELISA). The binders used in the ancient paintings of the Forbidden City and the Dazu Rock Carvings were detected by enzyme-linked immunosorbent assay (ELISA). The results showed that the binders of the Dazu Rock Carvings were diverse, including collagen, ovalbumin, casein, peach gum, and lacquer, and that collagen and peach gum coexisted in most samples of the Forbidden City. This study demonstrates ELISA's high efficiency in analyzing binders in ancient paintings.