Enamel proteins from six <i>Homo erectus</i> specimens across China

Protein extraction Animal fossils Powder was drilled from the dentin (Supplementary Data 1 ), then mixed with 1.5 ml of 0.6 M HCl for decalcification. The precipitate was washed with ultrapure water at least 3 times until the pH reached approximately 7. Then, 200 µl of 50 mM NH 4 HCO 3 was added, and the mixture was incubated at 65 °C for 3 h to extract soluble proteins. …