The invention disclosed herein relates to a sampling cannula for use in bone marrow biopsy procedures having structural features which facilitate sample retention within the device. In particular, the sampling cannula comprises an open trough-like portion, wherein the trough-like portion comprises at least one wall opening located proximal to the distal end in combination with an interior surface comprising a friction-enhancing surface texture adapted to facilitate sample retention. The invention further provides for a bone marrow biopsy system comprising an outer cannula having a sharpened distal tip, a sampling cannula having a distal trough portion in which the interior surface of the sampling cannula is exposed, at least one wall opening located within the trough portion located proximal to the distal tip of the sampling cannula, a friction-enhancing surface texture on at least a portion of the interior surface of the trough portion, wherein the sampling cannula is adapted to be inserted into an outer cannula and to sever a sample from the sampling site by rotational motion of the sampling cannula, and a stylet structured to be removably inserted into the outer cannula. The bone biopsy system can further include an ejector rod for expelling the retained sample from the sampling cannula.