A stopper and container body are molded in the same molding machine. An assembly device, such as a pick and place robot, transfers the stopper from one mold cavity into the opening in the container body located within another mold cavity, or vice versa, to assemble the stopper and container body. Then, the assembled container body and stopper are removed from the molding machine and transported to a needle filling and laser resealing station for filling and laser resealing. A laminar flow source directs a substantially laminar flow of air or sterile gas over the mold surfaces, stoppers and container bodies, and assembly device, to prevent contamination during assembly.