A biopsy sampling device has a trocar with sampling opening, an outer needle with 4 or more electrodes on it, an impedance measuring apparatus coupled to drive current through a first and a second electrode, while measuring voltages through a third and fourth electrodes to measure an impedance of tissue adjacent to the electrodes, the inner trocar within the central cavity of the outer needle such that its sharpened tip and sampling opening can protrude from an end of the outer needle and be removed to capture a sample in the sampling opening. In an embodiment, the electrodes are formed by inking an insulating tubular structure with a conductive ink. In an alternative embodiment, the electrodes are formed by winding conductive metal strips about an insulating tubular structure. In both embodiments, the metal strips or conductive ink is coated with an insulator in a central portion of the sampling device.
