NHA Certified Phlebotomy Technician (CPT)/Cheat sheet

NHA Certified Phlebotomy Technician (CPT) cheat sheet: key rules and summary

120 multiple-choice questions (100 scored + 20 pretest); scaled passing score 390/500; 2-hour limit.

  • 20 numbers
  • 4 sections
  • 5 rules people get wrong
Test yourself: 20 free questions Questions with answers

Every line checked against the CLSI GP41 Collection of Diagnostic Venous Blood Specimens & NHA CPT Blueprint on September 24, 2026. Print it, or keep it open while you practice.

Memorise these first

  • 1. Yellow / Blood CultureSPS (Sodium Polyanethol Sulfonate) or aerobic/anaerobic bottles — sterile collection first
  • 3–4 inversionsLight Blue (Sodium Citrate) — gentle inversion to prevent micro-clotting or hemolysis
  • 21 gauge (green)Standard routine adult venipuncture needle gauge (1 to 1.5 inches)

CLSI order of draw sequence

1. Yellow / Blood Culture
SPS (Sodium Polyanethol Sulfonate) or aerobic/anaerobic bottles — sterile collection firstCLSI GP41 — Order of Draw
2. Light Blue
Sodium Citrate (coagulation tests: PT, PTT, INR) — must fill completely to 9:1 ratioCLSI GP41 — Order of Draw
3. Red / Gold / SST
Serum separator tubes, clot activators (chemistry, serology, lipid panels)CLSI GP41 — Order of Draw
4. Green
Heparin (Lithium or Sodium heparin) — plasma chemistry determinations, STAT electrolytesCLSI GP41 — Order of Draw
5. Lavender / Purple
EDTA (K2 or K3 EDTA) — hematology (CBC, WBC, differential, Hgb/Hct)CLSI GP41 — Order of Draw
6. Gray
Sodium Fluoride & Potassium Oxalate (glycolytic inhibitor for glucose and BAC testing)CLSI GP41 — Order of Draw

Tube inversions by stopper color

3–4 inversions
Light Blue (Sodium Citrate) — gentle inversion to prevent micro-clotting or hemolysisSpecimen Collection — Mixing Specimens
5 inversions
Gold / Tiger Top / SST & Red plastic (clot activator)Specimen Collection — Mixing Specimens
0 inversions
Plain Red glass tube (no additive / clot activator)Specimen Collection — Mixing Specimens
8–10 inversions
Green (Heparin), Lavender (EDTA), Gray (Oxalate/Fluoride), Yellow (SPS)Specimen Collection — Mixing Specimens

Needles, angles and tourniquets

21 gauge (green)
Standard routine adult venipuncture needle gauge (1 to 1.5 inches)Equipment and Supplies — Needles
22 gauge (black)
Older children or adults with smaller veinsEquipment and Supplies — Needles
23 gauge (light blue)
Winged infusion (butterfly) needle for fragile, elderly, or pediatric veinsEquipment and Supplies — Needles
15° to 30°
Standard antecubital venipuncture insertion angle (bevel up)Venipuncture Procedure — Insertion Angle
10° to 15°
Dorsal hand venipuncture insertion angle using butterfly assemblyVenipuncture Procedure — Hand Veins
1 minute maximum
Tourniquet application time limit (longer than 1 min causes hemoconcentration)Venipuncture Procedure — Tourniquet Application
3 to 4 inches
Distance tourniquet is placed above the selected venipuncture siteVenipuncture Procedure — Tourniquet Application

Capillary heelstick specs

2.0 mm maximum
Maximum puncture depth for infant heelsticks to prevent osteomyelitis (bone infection)Capillary Punctures — Infant Heelsticks
Medial or lateral plantar
Safe heelstick puncture zone (never center of heel or posterior curve)Capillary Punctures — Infant Heelsticks
Wipe away first drop
Always wipe away the first drop of blood to eliminate interstitial fluid contaminationCapillary Punctures — Procedure

Second read

Rules people get wrong

  • The Light Blue (coagulation) tube requires a strict 9:1 blood-to-anticoagulant ratio. An underfilled tube falsely prolongs clotting times (PT/INR and aPTT) and will be rejected by the laboratory.
  • If using a winged infusion (butterfly) set and a coagulation (light blue) tube is drawn first, you MUST collect and discard a waste tube first to purge air from the tubing and avoid underfilling.
  • Drawing EDTA (lavender) before heparin (green) or serum (red/gold) causes cross-contamination with potassium and chelates calcium, causing falsely elevated K+ and falsely depressed Ca++.
  • Never leave a tourniquet on longer than 60 seconds while probing. Release the tourniquet as soon as blood flow is established in the first tube.
  • Vein selection order in the antecubital fossa: 1) Median cubital (first choice, best anchored), 2) Cephalic (second choice, lateral/outer arm), 3) Basilic (last choice, close to brachial artery and median nerve).

Take it with you

Save it as one poster

NHA Phlebotomy Technician (CPT) permit test cheat sheet: speed limits, distances, parking rules and the other numbers on the test, from the official handbook
The NHA Phlebotomy Technician (CPT) cheat sheet as one printable poster, every number from the official handbook. Download the full-size image

QuizCram (quizcram.com) · Verified against the official CLSI GP41 Collection of Diagnostic Venous Blood Specimens & NHA CPT Blueprint · Study online at quizcram.com/phlebotomy-practice-test

Knowing the numbers is half of it. Can you apply them?

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