Phlebotomy Equipment and Blood Collection Tubes - Key Terms

Vocabulary terms and definitions covering phlebotomy equipment, antiseptics, needles, evacuated tubes, additives, and the order of draw.

Phlebotomy Station

Outpatient drawing station that includes a phlebotomy chair with adjustable features and vein-locating aids.

Tourniquet

A device applied to the arm to impede venous blood flow and make veins more prominent for venipuncture.

BP cuff as tourniquet

A blood pressure cuff used as a tourniquet when appropriate, with proper training.

Vein Locator

Battery-operated device with high-intensity LED lights to help locate peripheral veins.

Alcohol prep (isopropyl alcohol)

70% alcohol used to clean the puncture site before venipuncture.

Povidone-iodine (Betadine)

Antiseptic used on skin; left on for 30–60 seconds; may interfere with some tests.

Chlorhexidine gluconate (CHG)

Antiseptic for blood cultures; not routinely used in infants under 2 months or if iodine allergy.

Benzalkonium chloride

Alternative antiseptic; used for blood cultures; caution with iodine allergy.

Cotton fibers in puncture site

Do not use cotton balls; fibers can contaminate clot and tear clot when removed.

Pressure to puncture site

Apply 2x2 inch sterile gauze after puncture; bleeding usually stops in minutes; longer with anticoagulants.

Needle hub

The part of the needle that attaches to a collection tube or syringe.

Needle gauge

Diameter of the needle lumen; larger gauge means smaller lumen and affects flow and tissue trauma.

Needle bevel

The angle/bevel of the needle to ease entry and reduce tissue trauma.

Needle point

The sharp tip of the needle that penetrates the skin smoothly.

Needle shaft length

Length of the needle; varies by vein depth and procedure.

Hub

Needle hub; connects the needle to the collection device.

Butterfly needle (Winged infusion set)

Flexible wings allow precise placement and manipulation for small or fragile veins.

Hypodermic syringe needle

Needle designed to attach to a syringe; used when vacuum tubes would collapse small veins.

Syringe needle sizing (22G, ~1 inch)

Common syringe needle size; size affects control and ease of access.

Syringe adapter

Adapter that connects syringe/needle to tubing or collection device; avoid mixing components from different manufacturers.

Evacuated collection tubes (Vacutainer)

Pre‑vacuum tubes that draw blood; maintain vacuum; come in various volumes depending on manufacturer.

Anticoagulants (general)

Substances added to prevent clotting: EDTA, citrate, heparin, potassium oxalate, sodium fluoride.

Sodium citrate

Anticoagulant used for coagulation studies; located in light blue top tubes; preserves plasma calcium.

EDTA

Anticoagulant that preserves cell integrity; used for CBC; found in lavender or pink tubes.

Heparin

Anticoagulant used for plasma chemistry tests; found in green (and sometimes green-gray) tubes.

Potassium oxalate

Anticoagulant used for glucose testing (often with sodium fluoride); found in gray tubes.

Sodium fluoride

Glycolysis inhibitor that preserves glucose for testing; often paired with potassium oxalate.

Clot activators

Substances (often silicone or clot activator) that promote clotting; used in serum tubes.

Silicone/micronized silica

Coatings in serum tubes to speed clotting and reduce RBC adherence.

Serum Separator Tube (SST) / Gold top

Serum tube with clot activator and gel separator to separate serum after centrifugation.

Thixotropic/polymer (gel)

Gel that forms a barrier between serum and cells during centrifugation.

PST (Plasma Separator Tube)

Heparinized tubes with gel; plasma separator; typically invert 8 times; no required clotting.

Royal Blue tube

Toxicology/trace metals testing; may contain KEDTA or none; designed to minimize contamination risk.

Tan tube

Lead analysis tube; contains K2EDTA; certified to have very low lead contamination.

Pink tube

Blood bank compatibility testing; K2EDTA; used for plasma or whole blood; compliant with AABB standards.

Yellow tube

Sterile blood culture tube; contains SPS (sodium polyanethol sulfonate); invert 8 times.

Blue top tube

Light blue; contains sodium citrate for coagulation studies; fill completely to maintain 9:1 blood-to-citrate ratio.

Red top tube

Plain serum tube (no additive) or serum with clot activator; used for serology/chemistry.

Orange top tube (RST)

Rapid serum tube with thrombin; very fast clotting; stat chemistry use; invert 5–8 times.

Order of draw

Sequence to minimize cross-contamination: Yellow (culture) → Light blue → Red/Discard → SST/Gold → Green → Lavender → Gray.

Needle disposal container

Puncture‑resistant, closable biohazard container for used needles; labeled with biohazard symbol.

Antiseptic

used to clean living tissue

disinfectant

used on inanimate surfaces

glycolysis

A metabolic process that breaks down glucose

smaller the gauge

larger the lumen

larger the gauge

smaller the lumen

largest diameter needles routinely used

21-22

blood bank uses what size

16-18 gauge

smallest needle used

23 gauge

multisample needles

allow multiple blood draws, have a hub that accommodates different tube sizes.

evacuation tubes

vacuum-sealed containers used for blood collection that minimize contamination.

point of vacuum in tubes

draws blood into tube easily

advantages and disadvantages of large needles

delivers blood faster but can cause damage to tissue

advatages and disadvantages of small needles

less tissue damage ut slower blood draw and chance of hemolyzation as they pass through

addatives

substances in blood collection tubes that improve or alter blood testing results.

SPS

Sodium polyethanol sulfonate, an additive in blood culture tubes that promotes the growth of microorganisms for testing.

how long does clotting take in tubes

in plain serum it takes 60 minutes, while serum with clot activator additives can take about 30 minutes to clot.

ABGs

Arterial blood gases, a test measuring oxygen and carbon dioxide levels in arterial blood.

what color tube doesn’t use any additives

A plain red glass tube, also known as a serum tube

green top tubes have

sodium heparin

sodium citrate is used in blood collection test for

coagulation studies, including Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT).

tube test inversions

The number of times a blood collection tube should be inverted after filling to ensure proper mixing of additives with the blood sample.

how many times should most tubes be inverted

5 to 10 times

Yes Be Ready to Stop Greet Listen Go

order of draw: Yellow, light blue, red no additives, SST Serum, green, lavender, Gray