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BIOCHEMISTRY PRACTICAL

Blood Collection (Phlebotomy)

Aim:

To collect a venous blood sample from a patient using aseptic techniques for diagnostic or research purposes.

Principle:

Blood collection involves puncturing a vein (usually in the antecubital region) to obtain blood. The process must be performed under sterile conditions to avoid contamination and ensure accurate laboratory results. Vacuum-based collection systems allow controlled blood flow into tubes with or without additives, depending on the required test.

Requirements:

Sterile gloves
Tourniquet
Alcohol swabs (70% isopropyl alcohol)
Sterile disposable needle
Vacutainer holder and blood collection tubes (EDTA, plain, etc.)
Gauze or cotton
Adhesive bandage
Sharps disposal container
Patient label and request form

Procedure:

Identify the patient and explain the procedure to gain consent.
Wash hands and wear sterile gloves.
Apply a tourniquet 3–4 inches above the selected vein (usually median cubital).
Ask the patient to make a fist (without pumping).
Clean the site with an alcohol swab and allow it to air dry.
Insert the needle into the vein at a 15–30° angle.
Attach the appropriate vacutainer tube and allow blood to flow in.
Once the required volume is collected, release the tourniquet and remove the needle.
Immediately apply gauze and pressure to stop bleeding.
Label the tubes, discard the needle in a sharps container, and remove gloves.
Send samples to the laboratory with a completed test requisition form.

Result:

A properly collected and labeled venous blood sample is obtained, free from contamination and hemolysis, ready for laboratory analysis.