A biopsy instrument comprising a base member formed of an elongated hollow tube which extends from a proximal end to a distal end along a central geometrical axis, wherein the elongated hollow tube comprises: an inner elongated hollow tubular member, which has, at a distal portion thereof, a hollow elongated tubular sample acquiring portion having a smooth interior surface, and which is formed of a polymer based material, and an outer elongated hollow tubular member, wherein the inner elongated hollow tubular member is arranged inside the outer elongated hollow tubular member and is rotationally and translationally movable relative to the outer elongated hollow tubular member, wherein the distal end of the inner elongated hollow tubular member is intended to be at least partly inserted into a tissue from which a biopsy is to be obtained, wherein the inner elongated hollow tubular member is provided with a distally facing circular cutting edge defining a mouth (1 0c) of the distal end (1 0b) of the hollow tube, characterised in that the inner elongated hollow tubular member is capable of transferring a force along the central geometrical axis such that a movement (LF, LB) of the proximal end along the central geometrical axis is transferred to a movement (LF, LB) of the distal end along the central geometrical axis, and of transferring a torque about the central geometrical axis such that a rotation (ω) and a torque applied by a motor at the proximal end about the central geometrical axis is transferred from the proximal end to the distal end thereby rotating the distal end about the central geometrical axis, wherein the smooth interior surface is smooth to such an extent that when a reference biopsy is to be acquired, the cutting edge and the distal end of the inner elongated hollow tubular member is configured to be advanced along the central geometrical axis into a tissue while being rotated (ω, T) by being motor driven at its proximal end and thereby cutting a core of the tissue which, due to the advancement of the inner elongated hollow tubular member, enters relative to the inner elongated hollow tubular member through the mouth into the sample acquiring portion of the inner elongated hollow tubular member with a circumferential outer surface of the core at least partly abutting the smooth interior surface of the sample acquiring portion, where-after the inner elongated hollow tubular member is retracted from the tissue while being rotated (ω, T) by being motor driven at its proximal end whereby the core of the tissue is detached from the tissue by a pulling force due to the retraction of the hollow tube and due to an adhesive force formed at an interface between the smooth interior surface and the circumferential outer surface of the core which force keeps the core inside the sample acquiring portion having the smooth interior surface. an inner elongated hollow tubular member, which has, at a distal portion thereof, a hollow elongated tubular sample acquiring portion having a smooth interior surface, and which is formed of a polymer based material, and an outer elongated hollow tubular member, wherein the inner elongated hollow tubular member is arranged inside the outer elongated hollow tubular member and is rotationally and translationally movable relative to the outer elongated hollow tubular member, wherein the distal end of the inner elongated hollow tubular member is intended to be at least partly inserted into a tissue from which a biopsy is to be obtained, wherein the inner elongated hollow tubular member is provided with a distally facing circular cutting edge defining a mouth (1 0c) of the distal end (1 0b) of the hollow tube, characterised in that the inner elongated hollow tubular member is capable of transferring a force along the central geometrical axis such that a movement (LF, LB) of the proximal end along the central geometrical axis is transferred to a movement (LF, LB) of the distal end along the central geometrical axis, and of transferring a torque about the central geometrical axis such that a rotation (ω) and a torque applied by a motor at the proximal end about the central geometrical axis is transferred from the proximal end to the distal end thereby rotating the distal end about the central geometrical axis, wherein the smooth interior surface is smooth to such an extent that when a reference biopsy is to be acquired, the cutting edge and the distal end of the inner elongated hollow tubular member is configured to be advanced along the central geometrical axis into a tissue while being rotated (ω, T) by being motor driven at its proximal end and thereby cutting a core of the tissue which, due to the advancement of the inner elongated hollow tubular member, enters relative to the inner elongated hollow tubular member through the mouth into the sample acquiring portion of the inner elongated hollow tubular member with a circumferential outer surface of the core at least partly abutting the smooth interior surface of the sample acquiring portion, where-after the inner elongated hollow tubular member is retracted from the tissue while being rotated (ω, T) by being motor driven at its proximal end whereby the core of the tissue is detached from the tissue by a pulling force due to the retraction of the hollow tube and due to an adhesive force formed at an interface between the smooth interior surface and the circumferential outer surface of the core which force keeps the core inside the sample acquiring portion having the smooth interior surface.