a blood collection assembly includes a plasma - treated blood collection container and a blood collector which optionally may also be plasma - treated . the collector has a body portion providing a blood passageway between the container and a scoop shaped portion which contacts a puncture wound . a vent in the collector allows air displacement from the container when blood enters . the inside wall of the container has longitudinal ribs molded thereon and an altered surface chemistry characterized by an enhanced oxygen content . the invention includes a method to increase blood flow across the interior surface of a plastic blood collection container comprising plasma treatment of the surface .