Devices for extracting bone marrow from a bone of a patient are disclosed. The device includes a housing defined in part by a cannula and a hollow needle disposed within the cannula. The hollow needle is movable axially relative to the cannula and extendable therefrom. The hollow needle is configured to aspirate bone marrow within a bone. A depth adjustment mechanism coupled to the hollow needle and the cannula is used to adjust the depth of the hollow needle relative to the cannula to control the distance of the needle within the bone. The device is attachable to an extraction device to extract bone marrow from the patient through the hollow needle. Methods of using these devices and methods of extracting bone marrow are also included.