Embodiments of the invention relate generally to protein extraction and, more generally, to bone protein extraction methods that do not require demineralization. In one embodiment, the invention provides a method comprising: mixing a bone sample and a quantity of an extraction buffer comprising: ammonium phosphate dibasic； or ammonium phosphate dibasic and ammonium bicarbonate； or ammonium phosphate dibasic, ammonium bicarbonate, and guanidine HCl； or sodium phosphate dibasic and sodium bicarbonate； or sodium phosphate dibasic, sodium bicarbonate, and guanidine HCl； or potassium phosphate dibasic and potassium bicarbonate； or potassium phosphate dibasic, potassium bicarbonate, and guanidine HCl； and incubating the bone sample/extraction buffer mixture.
