As mentioned previously, the problem with syringe blood collection is that the vacuum of the syringe is not controlled and consistent. Different individuals would pull the plunger faster or slower, which could create multiple errors in collection. If the blood is drawn too slowly, the specimen could start to clot, and the specimen could become useless. If the blood is drawn too fast, then there is a chance that the blood will hemolyze or that the vein could collapse under the vacuum pressure created by the syringe. The evacuated blood collection tubes have solved the problem of uncontrolled and inconsistent vacuum.
The original tubes were made from glass which presented the possibility of breakage and exposing the health care provider or patient to injury and bloodborne pathogens. Glass tubes, for the most part, have now been replaced by plastic tubes, which reduce the potential for tube breakage and specimen spillage, thereby reducing the potential for exposure to bloodborne pathogens.
