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.