Abstract: A sterile needle guide system for directing needle entry during a medical procedure includes a needle guide plate extending in a plane and having a plurality tubular needle guides extending through the plate at an normal angle to the plane of the plate. A movable base translatable along an axis normal to the plane of the plate defines features to removably receiving the plate. A calibrator attachment is removably securable to the needle guide plate and enables attachment of the needle guide plate to the base and calibration of the needle guide position in a sterile manner. In embodiments, the movable base includes a base body, a rail component over which the base body is movably coupled, and a ratchet mechanism for releasably securing the base body to the rail component. The disclosed needle guide system enables the needle guide plate to be positioned directly adjacent to the patient's perennial to reduce the curvature of deflection of the needle upon entry into the patient's body during the biopsy procedure.