A tissue separator assembly has an elongate tubular member and a tissue separator device located at a distal end of the elongate tubular member. An elongate coupler extends through the lumen of the elongate tubular member and has a distal coupler end. A tissue localization assembly has an elongate member and a localization device located at the distal end of the elongate member. The localization device may be movable from a first, radially-contracted state to a second, radially-expandable state. The distal coupler end of the elongate coupler and the proximal end of the elongate tubular member of the localization assembly are joinable to one another to permit docking of the tissue localization assembly to the tissue separator assembly. Methods of use of this device are also described.