['Closed suction drains are used in a variety of surgical procedures as a means of preventing hematoma formation or other fluid accumulation. The literature shows that they may be linked to postoperative infection. The aim of this study was to determine the timing of biofilm formation on drains, the route of colonization, and whether simple measures to increase sterility made any difference in biofilm formation.', 'A group of 12 patients, undergoing a variety of procedures, had drains removed at intervals between 2 and 42 hours. Cross-sections of these drains were sampled at three different sites: where the drain entered the skin, the middle of the drain, and the tip of the drain. The samples were sectioned longitudinally to view the lumen and outer wall. Specimens were viewed under scanning electron microscopy to compare the extent of biofilm formation in the drains on the left side with those on the right side. The drains on the left side were placed with increased attention to sterility.', 'Biofilm formation was evident on drains removed from as early as 2 hours after insertion. Statistical conclusions could not be drawn about route of colonization or enhanced sterility measures taken. From subjective analysis alone, route of colonization seemed to be a combination of on-table contamination and contamination from breast tissue. No difference in the amount of biofilm formation was found between normally inserted drains and those inserted with increased attention to sterility.'] Does pilot study of timing of biofilm formation on closed suction wound drain?