Sample Collection and anticoagulants.

1. COLLECTION OF BLOOD
&
ANTICOAGULANTS

2.  Why to collect blood..??
 For proper blood investigations to be done, obtaining
the specimen is the first and foremost step.
 Common examinations done on blood are..??
 Hematological
 Biochemical
 Serological
 Cultural

3. What are the Sites for sample collection..??
 Veins: Most commonly used.
 Capillaries.
 Arteries: In case of pediatric patients, ABG.

4.  Blood and its components:
 Whole blood
 Plasma
 Serum
 Red cells/PCV
 WBC
 Platelets

5. PHLEBOTOMY TRAY :
 Syringes & needles .
 Tourniquet
 Specimen containers . Plain bulb & anticoagulant bulbs.
 Request form
 70 % alcohol or 0.5% chlorhexidine
 Sterile gauze swabs
 Adhesive dressings
 Self sealing plastic bags
 Rack to hold the specimen containers.

6.  What is the Technique of blood collection..??
 Identification.
 Universal precautions.
 Inform the patient of the procedure/consent.
 Venous blood is best collected from the antecubital vein.
 The skin should be cleaned with 70% alcohol or 0.5 %
chlorhexidine & allowed to dry spontaneously.

7. INSTRUMENTS USED
IN COLLECTION OF
BLOOD &
TECHNIQUE

8.  The tourniquet should be tied just above the puncture site, which is
released once blood starts flowing into the syringe. Delay may lead to
haemoconcentration as a result of stagnation.
 Insert the needle through the skin at a plane parallel to the vein & care
should be taken that the vein doesn't get counter punctured.
 The piston of the syringe should not be withdrawn fast as it may cause
hemolysis.
 Sufficient amount of blood should be withdrawn and dispensed in
appropriate bulbs.
 The bulbs should be shaken for a while so that the blood gets mixed with
the anticoagulant properly.
 Remove the needle and apply a sterile swab over the site & apply pressure
over it. After the bleeding stops , apply a small adhesive dressing.
 BIO-MEDICAL WASTE MANAGEMENT..!!!!
 Complications..!!!

9. Various Types of bulbs..??

10.  CBC bulb (EDTA or double oxalate)
 Citrate bulb (trisodium citrate)
 Heparin bulb
 Blood sugar bulb (sodium flouride & k.oxalate)
 Urea bulb (potassium oxalate)
 Plain bulb
 Wide mouth bulb (for urine)
 Blood bags

11.  What are ANTICOAGULANTS..??
 Agents which prevent the coagulation of blood.
 DIFFERENT TYPES..
 EDTA (Ethylenediaminetetra Acetic acid)
 Trisodium Citrate
 Double oxalate
 Heparin
 ACD - Acid-citrate-dextrose
 CPD/CPDA - Citrate - phosphate - dextrose
/CPD+adenine

12.  EDTA (sequestrene/versene)- :
 Commonly used anticoagulant in routine practice.
 K/Na/Li salts of EDTA can be used.
 Mechanism Of Action:
It acts by chelating the calcium molecules in the blood.
 1.2 mg EDTA /ml of blood is required.
 EDTA is used for Hb. estimation, TLC, DLC, PS, hematocrit,
sickling test, reticulocyte count, hemoglobin electrophoresis.
 DISADVANTAGES:
• RBC morphology is hampered if the concentration is more than
the required.
• Not good for coagulation studies.

13.  Trisodium Citrate :
 It is used for coagulation studies.
 Mechanism of action :
It also works on the principle of calcium chelation.
 9 volumes of blood are added to 1 volume of 32gm/l sodium citrate
solution.
 For ESR estimation, 4 volumes of blood are added to 1 volume of
sodium citrate solution & well mixed.

14.  Double Oxalate:
 It contains
ammonium oxalate ( 3 parts)
potassium oxalate ( 2 parts )
 This combination minimizes the morphological changes that
occur in the erythrocytes.
 Mechanism of action :
Calcium chelation
 Uses - Routine hematological examinations & ESR
determination.
 Disadvantage: Crenation of red cells - cannot be used for making
blood films.

15.  HEPARIN:
 It is used for chemistry , blood gas analysis & emergency tests.
 It is the best anticoagulant for osmotic fragility tests &
immunophenotyping.
 The lithium or sodium salt of heparin at a concentration of 10- 20
IU / ml blood is generally used.
 It is not suitable for blood counts as it induces platelet &
leukocyte clumping & gives faint blue color on PS.

16.  ACD - acid – citrate - dextrose
 CPDA - citrate - phosphate - dextrose – adenine
 49ml/350ml of blood
 Uses- Blood bags for transfusion purposes
 Acid – provides optimum pH
 Citrate – Anticoagulant
 Dextrose – Nutrition
 Adenine & phosphate – Controls rate of glycolysis.

17. Additives –
 SODIUM FLUORIDE :
 It prevents glycolysis
 It is used for blood sugar estimation.

18. Thank you