A rapid and reliable method for analyzing millet and rice organic residues in archaeological samples

Archaeobotany plays a vital role in understanding the origins and development of agriculture. Given the different primary crops in northern and southern China, developing a method for distinguishing between millet and rice residues is crucial. Enzyme-linked immunosorbent assay (ELISA) has unique advantages in detecting animal organic residues, but its effectiveness in detecting plant residues remains uncertain. Therefore, this study devised an optimized ELISA method for the rapid, high-throughput identification of millet and rice residues in archaeological samples. The method exhibited satisfactory sensitivity and specificity, effectively detecting plant organic residues in both categories of archaeological samples. The method’s applicability and accuracy were cross-validated through documentary records, iodine–potassium iodide testing, and phytolith analysis. This study also represents a preliminary application of ELISA in archaeobotany. With further research, this technology has the potential to become a valuable tool in plant archaeology.