A disposable biopsy unit includes a biopsy needle unit and a pump. The biopsy needle unit includes a carrier, a biopsy needle and a cutting sheath. The carrier is configured to mount the biopsy needle and the cutting sheath. The cutting sheath is configured to move along a longitudinal axis relative to the biopsy needle. The pump has an elongate cylinder and a plunger. The plunger is configured to be movable inside the elongate cylinder in a first direction from a distal end of the elongate cylinder to a proximal end of the elongate cylinder to generate a vacuum and configured to be movable inside the elongate cylinder in a second direction from the proximal end of the elongate cylinder to the distal end of the elongate cylinder to build up pressure. The distal end of the elongate cylinder is coupled in fluid communication with the biopsy needle.