As the blood starts dripping into the collection tube, the tube should be rotated after each drop so the blood can contact the anticoagulant coating the inner walls of the tube. Once the tube is filled and capped, the specimen should be inverted 5 to 10 times for the blood to properly mix with the anticoagulant. If blood dripping is slow, the tube can be mixed while collection is still in progress so clotting of the specimen is prevented. Care needs to be taken while mixing the specimen because vigorous mixing will hemolyze the blood.
It is imperative that the healthcare provider performing the capillary blood collection is properly trained and understands not to combine specimens from one micocollection tube to another. This would contaminate the blood with the anticoagulant from the original tube and will affect the test results performed on the second tube.