Sample collected in  HMC facilities/others and transported to the lab within 1hour :
•    Collect sample into light blue-top (sodium citrate).
•    Tubes must be filled to within +/- 10% of their proper volume, to provide a 9:1 ratio of blood to citrate.
2-    Samples collected in  HMC facilities  / others  and which are   expected not to reach the lab within  1hour:

•    Centrifuge the whole blood and carefully remove the plasma by pipette not by decanting   and send the plasma  in a temperature-controlled environment (18-25ºC ) within one hour of centrifugation. 
•     If the transportation of  the plasma can’t be within a maximum of  2hour , prepare platelet-poor plasma  as follow:
A:    Re-centrifuge plasma again.
B:    Remove the top portion of plasma leaving approximately 250 mcL in the bottom to discard.
C:    The double-centrifuged plasma should be aliquoted (0.5 to 1 mL per aliquot) into labeled plastic tubes. The number of tests ordered will determine the aliquots needed.
D:    Freeze immediately at -20 ºC or below  .
E:    Specimens must arrive frozen.
3-    Sample for Platelets function studies (Platelets function assay) , Citrated whole blood should reach HMC within a maximum of 1-2 hours of collection.
4-     For heparin monitoring, follow the above mentioned steps.
5-    Consider patient HCT %. , if HCT is >55%, the volume of anticoagulant in the tube must  be adjusted by the referring  lab, as per  the below table shows the volume of citrate (µL) to be removed from common sizes of coagulation specimen tubes prior to specimen collection. After removal of the specified volume of citrate, enough blood is added to fill the tube to the ideal volume. .