order of draw study guide

Blood Culture Tubes

Used for detecting bacteria/fungi in the blood.

Light Blue Top (Citrate Tubes)

Used for coagulation studies (PT, PTT).

Red Top (Serum Tubes)

Used for serology and blood chemistry tests (no additives).

Gold/Speckled (SST) Tubes

Serum separator tubes for biochemistry tests; contains a gel that separates serum upon centrifugation.

Green Top (Heparin Tubes)

Used for plasma tests; contains heparin anticoagulant.

Lavender Top (EDTA Tubes)

Used for hematology tests (CBC) and blood bank (crossmatch).

Gray Top (Fluoride Oxalate Tubes)

Used for glucose testing and lactate measurements; contains fluoride which inhibits glycolysis.