Blood contamination during venepuncture and laboratory manipulations of specimen tubes.

The contamination of the working environment was assessed using a forensic screening test for blood during venepuncture, transport and laboratory manipulation of specimen tubes. Different methods of collecting blood and different commercially available specimen tubes were also assessed using an in vitro system. Blood collected by needle and syringe caused more environmental contamination than did an evacuated container system. Of the commercially available specimen tubes, those with screw tops produced least environmental contamination.