Free guides
Phlebotomy guides
Clear, WHO-based answers to the questions students actually search for — free to read, no sign-up. Each guide is an extract from the PhlebMastery theory course.
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the tourniquet sits, the one-minute limit that prevents haemoconcentration, and why it is released before the needle is withdrawn.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.
Looking for definitions instead? Browse the glossary of every term used across the course.