Blood Collection Tubes: Types, Additives and Uses
Understand the Effect of Additives on the Sample
Different kinds of tests need different types of samples. Others need whole blood; others need plasma or serum.
Anticoagulants stop clotting. Depending on the test and the method of processing the sample, the tubes containing these additives may contain whole blood or plasma.
Clot activators accelerate the clotting of blood, which allows for the isolation of serum after proper processing. Centrifugation produces separation gels that act as a barrier between the separated serum or plasma and the blood cells. Gel tubes still require the correct additive for the intended application.
For instance, BD’s serum separation tubes are supplied with clot activator and gel, and its plasma separation tubes are supplied with lithium heparin and gel. These products produce different specimens and should not be considered interchangeable.
Common Tube Types and Their Applications
Blood collection tubes are categorised into major types based on their additives and intended use.
EDTA tubes: These contain an anticoagulant and are commonly used in haematology investigations, including complete blood counts. Selected EDTA products are also suitable for immunohaematology testing. Lavender caps are frequently seen.
The most common tubes used for coagulation testing are sodium citrate tubes. Routine coagulation products usually contain 3.2% buffered sodium citrate. Proper filling is important to maintain the desired blood-to-additive ratio.
Serum tubes: These allow blood to clot and the serum to separate. Some have a clot activator. Serum separation tubes also contain a gel barrier and are used for laboratory tests that require that specimen and tube formulation.
Heparin tubes: Contains either lithium or sodium heparin to prevent clotting and allow for proper plasma chemistry tests. Some products have a separating gel.
Check colour, draw volume & handling instructions
Cap colours are useful visual cues, but product labels should confirm the choice.
Typical examples are lavender for EDTA, light blue for citrate, green for heparin and grey for some glucose tubes. But not all formulations are distinguished by colour alone. For example, Greiner Bio-One sells grey-cap tubes with various combinations of fluorides and anticoagulants.
Before use, check the additive, intended draw volume, product reference, and expiry date.
Filling is also a factor. A change in the blood-to-additive ratio due to underfilling or overfilling may affect the results of the analysis. Don't guess how much filling you need; follow the tube manufacturer's instructions for filling.
Why Elumia Med Store?
When you are looking for blood collection tubes in the UAE, a detailed product request will enable you to compare options with the approved specifications of your laboratory.
Elumia Med Store offers a contact point for any questions regarding products, quantities and current availability. Share the tube category, additive, draw volume, and dimensions and whether separation gel is required.
Check before you order:
- Manufacturer and product ref.
- Type of additive and concentration, if applicable.
- Compatibility with the collection system and work flow in the laboratory.
- Information about quantity and expiration.
- Manufacturer storage and handling instructions.
For teams purchasing blood collection tubes for clinics in the UAE, these checks make the inquiry more precise and help avoid ordering by cap colour alone.
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The first step in selecting blood collection tubes is the test and the specimen required. Draw volume. Processing instructions and additives. Then determine which product is appropriate.
Keep a laboratory-approved purchasing list and check proposed substitutions before ordering. Please confirm the label at the time of collection and follow the manufacturer's instructions and your facility protocol.
Please contact Elumia Med Store with your approved tube specifications to enquire about matching products, quantities and availability.