One adequately filled 3.0 mL light blue (sodium citrate) top tube.

**TIME SENSITIVE** For specimens that cannot be shipped to the laboratory to arrive within 4 hours of collection, see Collection and Processing of Coagulation Specimens information (link below).

Draw blood into the citrate tube (light blue cap) filled to the proper level (1 part anticoagulant to 9 parts blood). Invert tube 3-4 times to avoid clotting.

Specimens that are clotted, hemolyzed, collected in the wrong tube, less than 90% or greater than 110% filled, exceed stability limits or non-frozen plasma are unacceptable for testing.