A biopsy apparatus includes a cannula, a cutting sheath, a pressure generating device and a valve. The cannula has a lumen, a proximal portion, a closed distal end, and an orifice located on a circumferential surface of the cannula. The orifice is configured to receive a tissue sample into the lumen of the cannula. The cutting sheath is coaxially disposed with the cannula. The cutting sheath is configured to be movable relative to the cannula to selectively cover the orifice. The pressure generating device is coupled to the proximal portion of the cannula. A valve is interposed between the cannula and the pressure generating device. The valve is configured to control a flow of a fluid between the lumen of the cannula and the pressure generating device.
