Adult: 1 x 5 mL blue top sodium citrate tube (4.5 mL draw)
Pediatric: 1 x short-draw blue top sodium citrate tube (2.7 or 1.8 mL draw)
Whole blood
It is important to fill tube to maximum draw. Mix well.
Indicate collection time on tube.
Note: The preferred tube for adult collections is the 4.5 mL draw tube. For difficult draws, use the 2.7 mL short-draw tube.
Both APTT and prothrombin time/INR can be collected on one blue top tube.
When using a winged blood collection set (butterfly needle) a discard tube must be used to remove the air in the tubing, if only a citrate tube is drawn or is the first tube drawn. | 
