 FACT: When Cristina Peck wants to give blood to help Paul Rivers, a  nurse uses a blood collection system called Vacutainer to collect  her blood. This system uses the power of vacuum to collect blood. To  do this a vein has to be pricked with the needle and then a tube  must be pricked too with the other side of the needle then the  vacuum does the rest. In the film we see that the tube is already  pricked to the needle, so it wouldnt work.