The phlebotomy order of draw is an important protocol when collecting blood samples. It involves drawing and collecting blood using tubes in a specific order to avoid coagulant and anticoagulant contamination. This order helps to ensure sample accuracy and prevent clots from forming in the blood sample.
The generally accepted order of draw is as follows:
- Blood culture bottles – Sodium Polyanethol Sulfanate (Color varies, often a yellow top tube: used to minimize the risk of contamination with skin flora or other bacteria)
- Coagulation tubes – Sodium Citrate (Light blue top tube used for coagulation studies)
- Serum tubes – NO clot activator (Red top tube: used for chemistry, serology, and immunology tests)
- Serum Separator tubes (SST) – CONTAINS clot activator (Gold top tubes: used for chemistry, serology, and immunology tests)
- Heparin tubes – Sodium Heparin (Green top or light green top tubes: used for plasma chemistry and some specialized tests)
- EDTA tubes – Ethylenediaminetetraacetic acid (Lavender top or pink top tubes: used for hematology tests)
- Oxalate/fluoride tubes – Sodium Fluoride and Potassium Oxalate (Gray top tubes: used for glucose and lactate tests)
- ACD Solution – Acid Citrate Dextrose (Yellow top tubes: used for whole blood determinations including flow cytometry and tissue typing assays)
Printable Order of Draw Chart
It is important to note that some institutions or laboratories may have variations in the order of draw or specific protocols, so it is always best to follow the guidelines provided by the institution or laboratory where the phlebotomy is being performed.
How to remember the order of draw
For remembering order of draw based on tube colors, you can use a mnemonic such as this one:
Yellow Bananas, Red Grapes, Green Limes, Gone Yesterday!
- Y: Yellow tubes (used for blood cultures)
- B: Blue tubes (used for coagulation tests)
- R: Red tubes (used for serum tests)
- G: SST tubes (Serum Separator Tubes, which are also used for serum tests)
- G: Green tubes (used for plasma tests, such as electrolytes and ammonia)
- L: Lavender tubes (used for hematology tests, such as CBC and blood typing)
- G: Gray tubes (used for glucose and lactate tests)
- Y: Yellow tubes (used for flow cytometry and tissue typing assays)