This document provides information on different types of blood collection tubes including their purposes and contents. It discusses EDTA tubes which are used for complete blood counts and DNA isolation, citrate tubes which contain citrate and are used for prothrombin time tests, heparin tubes coated with heparin for karyotyping, gel tubes which separate plasma or serum from cells, plain red vials which separate serum after clot formation, and grey glucose vials containing sodium fluoride and potassium oxalate to prevent glucose consumption during processing. It emphasizes the importance of inverting tubes to mix anticoagulants and lists the recommended order of blood draw.

1. BLOOD
COLLECTIONTUBES

2. Colour coding ofVacutainers

3. EDTA tube (Lavender)
■ EDTA is Ethylene diamine tetra acetate – chelates calcium.
1.8mg EDTA/ml of blood

4. EDTA tube
■ Hemogram – RBC count, WBC count (Total/differential), Platelet
count
■ HbA1C estimation
■ Hemoglobin electrophoresis
■ DNA and RNA isolation
1.8mg EDTA/ml of blood

5. Importance of inversion of tubes
■ Allows proper mixing of anticoagulant.
■ An inversion is one complete turn of the wrist, 180 degrees, and
back.

6. Citrate tube (Blue)
■ 3.8%Trisodium citrate in liquid form.
■ Binds to calcium.
■ For Prothrombin time estimation: 1 part of citrate and 9 part of
blood. (1:9) ratio.
■ 200 microliter of citrate and 1.8 ml of blood.
■ For ESR estimation by Westergren method – 1:4 ratio.

7. Heparin tube (Green)
■ The walls of the tube are coated with either lithium heparin
or sodium heparin
■ Sodium results will only be 1 to 2 mmol/L higher.
■ Lithium heparin should not be used for lithium determinations
■ Heparin is derived from porcine intestinal mucosa.
■ Used for karyotyping.

8. Gel tubes (Yellow)
■ Plasma separation tubes (PST) or Serum separation tubes (SST)
■ The gel forms a physical barrier between serum or plasma and blood
cells during centrifugation.
■ Should be centrifuged between 30 minutes to 2 hours of collection.
■ Recentrifugation is not possible.

9. Gel tubes

10. Plain vial (Red)
■ Does not contain any anticoagulant.
■ May contain clot activators like kaolin.
■ After the formation of clot, serum separates.
■ Separation of serum is enhanced by centrifuging.
■ CSF sample should not be collected in clot activator vial.
■ Note: Do NOT refrigerate the blood sample.

11. Glucose vial (Grey)
■ Sodium fluoride and potassium oxalate are used as anticoagulant.
■ Fluoride is an inhibitor of the glycolytic enzyme enolase and thus
decrease the consumption of glucose by cellular component of
blood.
■ Samples of blood glucose estimation should be processed as soon as
possible.

12. Order of Draw
Tietz textbook of clinical chemistry 6th ed. P.107

13. Which of the following are wrongly
coloured?
■ Glucose
■ HbA1C
■ DNA isolation
■ Complete blood count
■ ProthrombinTime
■ Urea
■ Creatinine