Order of Draw for Blood Collection Tubes: Colour Chart
Drawing tubes in the right order stops additive from one tube contaminating the next. This chart gives the sequence, each tube's colour and additive, how many times to invert it and what it is used for.
What is the correct order of draw for blood collection tubes?
Following CLSI GP41, draw in this order: 1. blood culture bottles, 2. sodium citrate (light blue), 3. serum tubes with or without clot activator or gel (red, gold), 4. heparin (green), 5. EDTA (lavender), 6. sodium fluoride / potassium oxalate (grey). The order keeps additives such as EDTA out of tubes where they would distort results, for example potassium and calcium.
Order of draw chart
| Order | Tube | Additive | Inversions | Common tests |
|---|---|---|---|---|
| 1 | Blood culture bottles | Culture medium | Per maker | Blood cultures (sterile draw) |
| 2 | Light blue | Sodium citrate 3.2% | 3–4 | Coagulation: PT/INR, APTT |
| 3 | Red | Clot activator or none | 5 | Serum chemistry, serology |
| 3 | Gold / yellow (SST) | Clot activator and gel | 5 | Serum chemistry, hormones |
| 4 | Green / light green | Lithium or sodium heparin (± gel) | 8–10 | Plasma chemistry, electrolytes |
| 5 | Lavender / purple | K2 or K3 EDTA | 8–10 | Full blood count, HbA1c |
| 6 | Grey | Sodium fluoride / potassium oxalate | 8–10 | Glucose, lactate |
Inversion counts are typical; follow the tube manufacturer's instructions. Some laboratories place the ESR tube (black cap, citrate 1:4) after citrate; follow your laboratory's protocol.
We manufacture vacuum blood collection tubes in every cap colour, citrate, serum, SST, heparin, EDTA and fluoride, made to ISO 6710.
Frequently asked questions
Why does the order of draw matter?
Each tube contains an additive, and a little can carry over on the needle into the next tube. EDTA carried into a serum or heparin tube, for example, can raise potassium and lower calcium results falsely. Drawing in a fixed order prevents this.
Which tube is drawn first?
Blood culture bottles, to keep the sample sterile. If no culture is needed, the light blue citrate tube usually comes first; when it is the first tube with a winged set, draw a discard tube to fill the tubing dead space.
What colour is an EDTA tube?
Lavender or purple. It holds K2 or K3 EDTA and is used for full blood counts and HbA1c; pink EDTA tubes are used for blood bank samples.
How many times should a blood tube be inverted?
Typically 3–4 times for citrate, 5 for serum tubes with clot activator, and 8–10 for heparin, EDTA and fluoride tubes. Invert gently and follow the tube maker's instructions.
Which tube is used for glucose?
The grey tube with sodium fluoride and potassium oxalate, which stops cells using up glucose after the sample is taken.
Buyer guides on this topic
- Blood Collection Tube Colors Explained: SST, Heparin, EDTA and ESR
- Vacuum Blood Collection Tubes: Clot Activator, K2/K3 EDTA & Sodium Citrate Draw Accuracy per ISO 6710
- Vacuum Blood Collection Tubes, Needles & Lab Disposables: Pathology Procurement Guide
More free charts and calculators
Use this chart on your site
Hospitals, nursing schools, trainers and distributors are welcome to link to it. Copy this:
<a href="https://www.manshavimpex.com/tools/blood-collection-tube-order-of-draw">Order of Draw for Blood Collection Tubes: Colour Chart</a> (Manshav Impex)