1. Perform Blood Collection
Evacuated Tubes
Perform Blood Collection

2. Evacuated Tubes Blood collected straight into tube
Made of plastic or glass
Come in different sizes and volumes
Size determined by lab request, age, size and condition of vein.
Glass are coated with silicon to fill tiny cracks and create smooth surface. Also helps to prevent clotting factors from activating

3. Evacuated Tubes
Tubes fill automatically due to vacuum which is premeasured by manufacturer. If vacuum is lost, tube will not fill
Some tubes contain additives which is any substance placed in a tube
Integrity of vacuum is guaranteed within expiry date. Can be compromised if out of temp range or dropped
Tube stoppers usually made of rubber and plastic

4. Evacuated Tubes
Colour coding – top of tube is coloured to indicate presence and type of additive
Non-additive tubes – blood will clot within 60 mins
Additive tubes – may or may not clot depending on additive. Amount of additive is preset to function with correct amount of blood

5. Additives Never transfer blood from tube to tube
Available in liquid or dry forms
Tubes should be gently inverted 3-10 times immediately after collection
EDTA
Prevents clotting by binding CA
Mainly used for haematology
Must be mixed immediately to prevent platelet clumping
Examples of use – FBC, HB,wcc,rcc pcv,mcv,mch mchc,wbc

6. Additives Citrates Use for anticoagulation therapy
Prevents clotting by binding CA
Most common is sodium citrate – blue tube
Requires mixing
Vital to fill to correct level
Examples are INR, PT, PI, PR, APTT

7. Additives Heparin Plain with separator gel
Prevents clotting by inhibiting thrombin
Thrombin is needed to convert fibrinogen into fibrin, necessary for clot formation
Types are Ammonium, Lithium and Sodium Heparin
Lithium Hep is most widely used
Mix immediately after collection
Usually used for drug levels and some chem. tests

8. Tubes and additives Oxalates Used for glucose testing
Mix immediately after collection
Examples are – glucose, BSL

9. Tubes and additives Clot tubes Most other tests
Examples are – lipids, pregnancy test, cardiac enzymes