Free phlebotomy guides

• Order of draw · 6-min read

  Order of draw: tube colours, additives, and the WHO sequence

  Why multiple tubes are drawn in a fixed order, the WHO/CLSI sequence, and what each tube colour and additive does.

• Antecubital vein selection · 7-min read

  Antecubital fossa vein selection: median cubital, cephalic, and basilic

  The three veins of the antecubital fossa, why the median cubital is first choice, and the structures a safe draw avoids.

• Haemolysis causes · 6-min read

  Haemolysis: causes and how to prevent specimen rejection

  The most common cause of specimen rejection — what destroys red cells during a draw, and how to prevent it.

• Tube colours & additives · 6-min read

  Tube colours and additives: what each blood collection tube does

  What the additive in each tube colour does, why additive tubes must be filled to the line, and why mixing is by gentle inversion.

• Needle gauge selection · 5-min read

  Needle gauge selection: which gauge for which draw

  Why the gauge number runs backwards, the 21G routine-adult default, and the two failure modes — vein trauma and haemolysis.

• Vacutainer vs syringe · 5-min read

  Vacutainer vs syringe: which blood collection system to use

  Why WHO prefers the closed evacuated tube system, how the open syringe system differs, and when to choose each.

• Tourniquet technique & timing · 5-min read

  Tourniquet technique and timing: placement, timing, and release

  Where the tourniquet sits, the one-minute limit that prevents haemoconcentration, and why it is released before the needle is withdrawn.

• Venepuncture procedure · 7-min read

  Venepuncture step by step: the WHO procedure end to end

  The WHO venepuncture procedure end to end — from patient identification and antisepsis through needle insertion to safe post-puncture care.

• Venepuncture complications · 7-min read

  Venepuncture complications: haematoma, fainting, nerve injury, and failed draws

  The four complications a phlebotomist meets most — the bruise, the faint, the nerve, and the draw that will not come — and the response to each.

• Venepuncture vs venipuncture · 4-min read

  Venepuncture vs venipuncture: spelling, meaning, and the difference

  Why the procedure is spelled two ways, what venepuncture means, and how it differs from phlebotomy and capillary collection.

• Hand hygiene & sharps safety · 8-min read

  Hand hygiene and sharps safety: the WHO five moments and needlestick response

  The infection-control habits behind every safe draw: the WHO five moments, safe sharps handling, and what to do after a needlestick.

• Specimen rejection · 6-min read

  Specimen rejection: why blood samples get rejected and how to prevent it

  The reasons a laboratory rejects a sample — haemolysis, clotting, under-filling, mislabelling — and the practice that prevents each.

• Finding a vein · 7-min read

  How to find a vein: palpation, the antecubital fossa, and difficult veins

  Where to look, how a good vein feels under the finger, and how to bring a shy vein into view — finding a vein by touch, not just sight.

• Blood cultures · 6-min read

  Blood cultures: contamination, skin antisepsis, and bottle order

  Why blood cultures are the easiest sample to contaminate, the enhanced antisepsis that prevents it, and the aerobic-first bottle order.

• Capillary blood sampling · 6-min read

  Capillary blood sampling: finger-stick and neonatal heel-stick

  When a skin puncture beats a vein, the heel-versus-fingertip site rule by age, lancet depth, and the handling that protects the sample.

• Paediatric venepuncture · 6-min read

  Paediatric venepuncture: equipment, holding, and pain management

  The same draw, rescaled to a small patient: a finer butterfly, low-vacuum tubes, a planned hold, and honest pain management.

• Arterial blood gas & Allen test · 6-min read

  Arterial blood gas and the modified Allen test

  What an ABG is for, why it is competency-gated and radial-first, and how the modified Allen test confirms the ulnar supply before puncture.

• Patient identification · 6-min read

  Patient identification: the two-identifier rule in phlebotomy

  Why identification is the most important non-technical step, the two identifiers required, and why active identification is the only acceptable check.

• Tourniquet timing · 5-min read

  How long can a tourniquet stay on? The one-minute rule

  The one-minute limit explained — why a prolonged tourniquet falsely raises potassium and other analytes, and what to do if the vein takes longer to find.

• Tube inversion counts · 5-min read

  Tube inversion counts: how many times to mix each blood tube

  The typical inversion count for each tube additive, why prompt mixing prevents clotting, and why shaking causes haemolysis.

• Needlestick response · 6-min read

  Needlestick injury: what to do immediately after a sharps injury

  The first-minutes response to a sharps injury — bleed, wash, report, document — and why prompt reporting preserves effective post-exposure prophylaxis.

• Vasovagal fainting · 6-min read

  Fainting during a blood draw: the vasovagal reaction

  How to spot a vasovagal faint before it happens, why lying the patient flat is the key response, and how to prevent the dangerous fall.

• Antecubital vein comparison · 6-min read

  Median cubital vs cephalic vs basilic vein: which to choose

  The three elbow veins ranked by preference, where each sits, and why the basilic carries the highest risk of arterial puncture and nerve injury.

• Order of draw mnemonic · 5-min read

  Order of draw mnemonic: how to remember the tube sequence

  A common order-of-draw mnemonic mapped to the tube colours, plus the additive-carryover reasoning that makes the sequence make sense.

Looking for definitions instead? Browse the glossary of every term used across the course.

These guides are independent educational materials. They are informed by published WHO phlebotomy guidance and other professional references; they are not WHO materials and are not endorsed or accredited by WHO.