Phlebotomy flashcards
Seventy-two free phlebotomy flashcards on tubes, the order of draw, venipuncture, capillary collection, safety, patient identification, and specimen handling. These are original, unofficial cards for United States phlebotomy, supporting supervised training rather than replacing it.
Tubes, additives, and the order of draw (16 cards)
PHF-001 · Card 1 of 72For routine venous collection, what is the order of draw?Show answer
- Blood culture tube or bottle.
- Sodium citrate — blue closure.
- Serum tubes, including those with clot activator and gels — red, red-speckled, gold.
- Heparin with or without gel — dark green, light green, speckled green.
- EDTA with or without gel separator — lavender, pearl, pink.
- Sodium fluoride / potassium oxalate glycolytic inhibitor — gray.
Why: CLSI publishes the same six groups whether you collect by syringe, tube holder, or evacuated tube. Group three is serum tubes generally, not only the ones with clot activator.
PHF-002 · Card 2 of 72Why does the venous order of draw exist at all?Show answer
To reduce the risk of one tube's additive carrying over on the needle into the next tube and changing that specimen's result.
Why: The sequence protects the tube you have not filled yet. That is why it is a chain of reasoning, not a colour mnemonic.
PHF-003 · Card 3 of 72Can a serum tube ever be collected before the citrate tube?Show answer
Only three things may come before it: a blood culture tube, a glass non-additive serum tube, or a plastic serum tube without clot activator. A plastic serum tube that contains a clot activator may interfere with coagulation testing.
Why: This is the qualifier CLSI prints under its own list, and it answers the question students actually ask — "can I draw a red before a blue?" The answer is: which red? Labcorp's coagulation guidance says the same thing from the other direction, putting gel-barrier tubes and serum tubes with clot initiators after the citrate tube.
PHF-004 · Card 4 of 72What is in a routine light-blue coagulation tube?Show answer
Sodium citrate, an anticoagulant. Labcorp specifies 3.2% buffered sodium citrate for coagulation collection.
Why: Citrate works by binding calcium, which the clotting cascade needs. The concentration matters: reference intervals are built on a stated citrate strength, not on "a blue cap."
PHF-005 · Card 5 of 72Why must a citrate tube be filled to completion?Show answer
To keep the 9:1 blood-to-anticoagulant ratio. Under-filling raises the anticoagulant-to-blood ratio and can extend clot-based coagulation assays.
Why: A short blue tube may be rejected, or it may produce a falsely long clotting time if the problem is missed. The fill requirement protects the result somebody may act on.
PHF-006 · Card 6 of 72You have two under-filled citrate tubes. Can you pour them together to make one full specimen?Show answer
No. Labcorp's instruction is explicit: never combine two under-filled tubes.
Why: Two wrong ratios do not average into a right one, and you would also be pooling two separately handled specimens.
PHF-007 · Card 7 of 72A citrate tube is the first specimen drawn through a new winged (butterfly) collection set. What goes on first?Show answer
A discard tube, to fill the tubing with blood before collecting the citrate specimen. Without it, the air in the tubing can leave the citrate tube under-filled.
Why: The discard tube does not need to be full. Its job here is to clear the air from the line so the citrate tube can fill to its mark. Use the discard tube specified by the device and laboratory instructions.
PHF-008 · Card 8 of 72Does a routine straight-needle coagulation draw need a discard tube first?Show answer
No. Labcorp does not require a discard tube for routine direct venipuncture before coagulation collection. Its winged-set instruction is different; blood drawn through an intravascular line also has separate clearing requirements.
Why: The collection setup matters. Do not turn the winged-set rule into a rule for every citrate draw, or apply a straight-needle rule to a line draw.
PHF-009 · Card 9 of 72What does a lavender-top tube contain, and what is it usually collecting for?Show answer
EDTA, an anticoagulant (ethylenediaminetetraacetic acid). It is the routine whole-blood tube for haematology work such as a complete blood count.
Why: A CBC counts the cells themselves, so the specimen has to stay unclotted whole blood. Serum will not substitute for it.
PHF-010 · Card 10 of 72Why can potassium-EDTA carryover distort both coagulation and chemistry results?Show answer
EDTA binds calcium, so contamination can interfere with coagulation testing. Potassium-EDTA also introduces potassium that was never in the patient, causing a falsely high potassium result; calcium results can be falsely low.
Why: One additive, two different ways to produce a confidently wrong number. That is why EDTA sits near the end of the sequence.
PHF-011 · Card 11 of 72What do the clot activator and the gel do in a gold serum-separator tube?Show answer
The clot activator speeds up clotting; the gel forms a barrier between serum and cells during centrifugation.
Why: Neither is an anticoagulant. This tube deliberately makes the blood clot, so it yields serum, not plasma.
PHF-012 · Card 12 of 72Does a red cap guarantee a tube with no additive?Show answer
No. BD lists red closures for silicone-coated serum tubes, and plastic serum tubes can carry a clot activator. "No anticoagulant" is not the same as "no additive."
Why: This is exactly why the order-of-draw exception is worded around clot activator rather than around the colour red.
PHF-013 · Card 13 of 72What additive is in a green-top tube?Show answer
Heparin — which may be lithium heparin or sodium heparin, with a gel version in light green.
Why: The cation matters. A lithium heparin tube is the wrong tube for a lithium level, and the label, not the colour, tells you which one you are holding.
PHF-014 · Card 14 of 72In a gray-top sodium fluoride/potassium oxalate tube, which ingredient limits glucose breakdown?Show answer
Sodium fluoride is the antiglycolytic agent — it inhibits glucose breakdown. Potassium oxalate is the anticoagulant, doing a different job. Fluoride does not stop glycolysis immediately, so the laboratory's glucose-handling requirements still matter.
Why: Two ingredients, two jobs. Saying "gray has oxalate" describes half the tube and the wrong half for the question being asked. Read the formulation: not every gray tube contains the same additives.
PHF-015 · Card 15 of 72Where does a royal-blue trace-element tube go in the order of draw?Show answer
Find out what is in it first, then place it by its additive. BD makes royal-blue tubes in a clot-activator serum version and a K2EDTA version.
Why: CLSI's own instruction for any tube outside the six groups is to place it by the carryover risk its additive creates. One closure colour cannot hold two positions at once.
PHF-016 · Card 16 of 72How many times should you invert a tube after collection?Show answer
Gently, the number of times that tube's manufacturer specifies. BD publishes 3–4 inversions for its sodium citrate tube and 8 for EDTA; Greiner Bio-One publishes 4 for its coagulation tube and 8–10 for EDTA.
Why: Inversion counts are manufacturer specifications, not universal facts — which is why your handout and your textbook can both be right. Learn what inversions do: too few can leave the additive poorly mixed; anticoagulant tubes may clot, while clot-activator tubes may clot incompletely. Shaking can damage red cells.
Showing all 72 cards.
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Routine venipuncture (12 cards)
PHF-017 · Card 17 of 72What is WHO's guidance for choosing a vein?Show answer
Select a large, firm vein, preferably in the antecubital fossa, in an area free of skin lesions or scars. Extend the arm, inspect, and look for a vein of good size that is visible, straight and clear.
Why: Notice what is not on that list: "whichever one you can see." Size, firmness and clear skin come first, and your program's site-selection teaching and your facility's procedure govern the final choice.
PHF-018 · Card 18 of 72A patient reports sudden sharp or shooting pain as the needle goes in. What do you do?Show answer
Stop the draw immediately. Release the tourniquet if it is still on, remove the needle, and report the event under your facility's procedure.
Why: Sudden shooting pain can signal nerve injury, not a normal part of the procedure to push through. The DynaLIFE procedure explicitly says to terminate collection immediately for this symptom.
PHF-019 · Card 19 of 72How long may the tourniquet stay on?Show answer
Use the laboratory's limit; Labcorp's instruction is never longer than one minute. Release the tourniquet as soon as blood flow is established, and always before withdrawing the needle.
Why: Prolonged application can cause hemoconcentration — a change in the concentration of blood components that distorts results. WHO's 2010 global text mentions a two-minute boundary, but that is not permission to exceed your laboratory's stricter one-minute limit.
PHF-020 · Card 20 of 72Tourniquet or needle — which comes off first?Show answer
The tourniquet. WHO's procedure is to release the tourniquet before withdrawing the needle.
Why: Releasing first drops the pressure inside the vein, so there is less to leak into the tissue when the needle comes out.
PHF-021 · Card 21 of 72In WHO's routine 70% alcohol venipuncture preparation, how is the antiseptic applied?Show answer
Start at the centre of the site and work downward and outward to cover 2 cm or more, then allow the area to dry.
Why: This is WHO's routine alcohol-swab procedure, not a universal instruction for every antiseptic or for blood cultures. Meet the antiseptic's required contact time and let the site dry; do not treat drying as an optional pause.
PHF-022 · Card 22 of 72You cleaned the site, then rested a finger on the vein to check it. What now?Show answer
Repeat the disinfection. WHO's instruction is explicit: do not touch the cleaned site, and in particular do not place a finger over the vein to guide the needle. If the site is touched, disinfect again.
Why: Touching can recontaminate the site. The earlier cleaning does not protect it from a new contact.
PHF-023 · Card 23 of 72Where does your thumb go when you anchor the vein?Show answer
Below the venepuncture site. Hold the patient's arm and place the thumb below the site to anchor the vein.
Why: Anchoring from below pulls the skin taut without putting your hand in the needle's path.
PHF-024 · Card 24 of 72At what angle does the needle enter the vein?Show answer
30 degrees or less. Enter the vein swiftly, then continue along the vein at the easiest angle of entry.
Why: A steep angle is more likely to go through the back wall of the vein than into it.
PHF-025 · Card 25 of 72Why does a difficult, traumatic venipuncture matter beyond the patient's comfort?Show answer
It can damage or activate the specimen. Labcorp's guidance is that the venipuncture should be clean and minimally traumatic, and that severely hemolysed samples are not acceptable for its coagulation testing.
Why: Technique is a pre-analytical variable. A specimen collected badly can be rejected, which means the patient gets stuck again.
PHF-026 · Card 26 of 72Does Labcorp's coagulation guidance mean a 23-gauge needle is never suitable for phlebotomy?Show answer
No. That passage belongs to Labcorp's coagulation specimen guidance. WHO's blood-sampling table includes 23-gauge devices for phlebotomy, and its guidance is to choose a gauge that fits the vein comfortably.
Why: Needle choice depends on the patient, vein, device and specimen requirements. A line in one laboratory's coagulation instructions is not a universal minimum needle size for every collection.
PHF-027 · Card 27 of 72Does the material a tube is made of matter for coagulation testing?Show answer
Yes. Labcorp specifies non-reactive or non-wettable containers such as siliconised glass or plastic, and states that borosilicate, soda lime, or soft glass tubes cannot be used because they can activate the contact pathway of coagulation.
Why: The tube is not a neutral cup. For coagulation work it is part of the test system.
PHF-028 · Card 28 of 72A patient's hematocrit is known to be above 55%. What changes about the coagulation draw?Show answer
The amount of citrate in the tube has to be reduced using the laboratory's calculation. Arrange a laboratory-prepared or laboratory-approved adjusted citrate tube before collection; do not estimate the adjustment at the chair.
Why: A high hematocrit means less plasma for the same volume of whole blood, so the standard citrate load is effectively too concentrated. This is a laboratory calculation, not something to estimate at the chair.
Capillary collection (7 cards)
PHF-029 · Card 29 of 72For routine BD Microtainer collection that does not include blood gases, what is the order?Show answer
EDTA tubes, then other additive tubes, then serum tubes. WHO's capillary guidance likewise says to start with haematology specimens.
Why: This card is scoped to routine laboratory microcollection. Capillary blood gases need their own procedure; do not apply this three-group list to a collection that includes them.
PHF-030 · Card 30 of 72Why does routine capillary microcollection prioritize EDTA, unlike the venous order?Show answer
Different problem. The venous sequence reduces additive carryover. In routine capillary microcollection without blood gases, collecting hematology specimens early helps limit the effect of platelet clumping and clotting.
Why: Learn the two reasons, not two lists. Then you can tell which one a question is about.
PHF-031 · Card 31 of 72BD's own capillary order-of-draw FAQ cites a CLSI document from September 2008. What is the current one?Show answer
CLSI GP42, Collection of Capillary Blood Specimens, 7th edition, published 16 September 2020. It replaced GP42-A6 from 2008 and kept its GP42 designation, while venous collection was renumbered from GP41 to PRE02.
Why: The current capillary standard is GP42, 7th edition. The older date in the BD FAQ is its cited reference, not the date of the current standard. Check the exact document and edition rather than guessing a new code from the venous renaming.
PHF-032 · Card 32 of 72What happens to the first drop of blood after a skin puncture?Show answer
Wipe it away. It may be contaminated with tissue fluid or with debris such as sloughing skin.
Why: This is a routine laboratory microcollection instruction. A point-of-care meter has its own manufacturer's procedure, which may differ.
PHF-033 · Card 33 of 72Why not squeeze the finger or heel harder to speed up a capillary collection?Show answer
Squeezing too tightly dilutes the specimen with tissue fluid and increases the chance of hemolysis.
Why: Harder is not faster to an equivalent specimen. It can change the sample you are trying to collect.
PHF-034 · Card 34 of 72Finger or heel — which site, for which patient?Show answer
The finger is usually the preferred site for capillary testing in an adult. When a heel puncture is appropriate for an infant, the medial or lateral plantar areas — the inner or outer underside — are used, not the posterior curve or central heel. Paediatric site selection depends on age, weight and the device instructions.
Why: Age and weight, not habit, drive the paediatric choice. This card does not set a lancet depth; that is device- and protocol-specific.
PHF-035 · Card 35 of 72Immediately after capillary sampling, how do you control bleeding at the puncture site?Show answer
Apply firm pressure to the site to stop the bleeding.
Why: A skin puncture is a wound. Confirming it has stopped bleeding is part of the procedure, not an optional courtesy.
Safety and infection prevention (12 cards)
PHF-036 · Card 36 of 72Is recapping a contaminated needle ever permitted under OSHA?Show answer
Only under a narrow exception. Contaminated needles must not be bent, recapped, or removed unless the employer can demonstrate that no alternative is feasible or the action is required by a specific medical or dental procedure — and then only with a mechanical device or a one-handed technique.
Why: For a routine draw, do not recap. Knowing that the regulation contains an exception does not make recapping a routine option.
PHF-037 · Card 37 of 72After a routine draw, what happens to the needle?Show answer
Engage its safety feature as the manufacturer instructs and dispose of the assembly in an appropriate sharps container. A routine draw is not one of the narrow situations where recapping is permitted.
Why: Engineering controls such as safety-engineered needles and sharps containers isolate or remove a hazard. OSHA requires engineering and work practice controls to eliminate or minimize employee exposure.
PHF-038 · Card 38 of 72OSHA uses prohibiting two-handed needle recapping as an example of what kind of control?Show answer
A work practice control — one that reduces exposure by changing how a task is performed. An engineering control is different: it isolates or removes the hazard, like a sharps disposal container or a self-sheathing needle.
Why: For this distinction, ask whether a device isolates the hazard or a rule changes how the person performs the task. Two-handed recapping itself is not a protective control; prohibiting it is.
PHF-039 · Card 39 of 72Which activities does OSHA prohibit in work areas where occupational exposure is reasonably likely?Show answer
Eating, drinking, smoking, applying cosmetics, applying lip balm, and handling contact lenses.
Why: The rule includes lip balm and contact lenses, not just food and drink. It applies where occupational exposure is reasonably likely.
PHF-040 · Card 40 of 72When must an employer make hepatitis B vaccination available, and who pays?Show answer
Within 10 working days of initial assignment to a job with occupational exposure, at no cost to the employee, after bloodborne pathogens training. Exceptions apply when the employee has completed the vaccination series, antibody testing shows immunity, or vaccination is medically contraindicated. An employee who declines must sign the required declination and can accept later while still covered by the standard.
Why: The timing, the cost, the exceptions and the signed declination are all part of the rule. An employer cannot make prescreening a condition of receiving the vaccine.
PHF-041 · Card 41 of 72Under Universal Precautions, whose blood is treated as infectious?Show answer
Everyone's. All human blood and certain human body fluids are handled as if known to be infectious for HIV, hepatitis B, and other bloodborne pathogens, regardless of the patient's diagnosis.
Why: A reported negative infection status does not remove bloodborne precautions. Standard Precautions apply to all patients; additional precautions may be needed for particular infections or exposure risks.
PHF-042 · Card 42 of 72Do Standard Precautions apply only to patients with a known infection?Show answer
No. CDC applies them to the care of all patients, with the protection chosen for the exposure you reasonably anticipate.
Why: Not every collection calls for the same gear. Splash risk changes what you put on; it does not change whether precautions apply.
PHF-043 · Card 43 of 72When is hand hygiene needed around glove use?Show answer
Before putting gloves on for patient contact, and again after taking them off.
Why: Gloves are a barrier, not a substitute. Hands can become contaminated during removal, so clean them after taking gloves off.
PHF-044 · Card 44 of 72Your hands are visibly soiled. Alcohol rub or soap and water?Show answer
Soap and water.
Why: Alcohol-based hand rub is the routine choice in health care, but it is not the answer for visibly dirty hands.
PHF-045 · Card 45 of 72Where should the sharps container be while you are working?Show answer
Easily accessible, as close as feasible to the immediate area of use, kept upright, and replaced routinely rather than allowed to overfill.
Why: Safe disposal should never require carrying an exposed sharp across a room.
PHF-046 · Card 46 of 72A specimen tube has blood on the outside of it. What does OSHA require?Show answer
Put it inside a second container that prevents leakage and is labelled or colour-coded for biohazard, before it is handled, stored, or transported.
Why: An outside-contaminated tube is a contaminated surface. The secondary container limits exposure during the next handling step; it does not remove the need for appropriate precautions.
PHF-047 · Card 47 of 72You have a needlestick injury. What does your employer have to provide?Show answer
A confidential medical evaluation and follow-up, made immediately available after you report the exposure incident. Wash the puncture with soap and water, report it immediately, and seek prompt medical care under your facility's exposure procedure.
Why: First aid, reporting and medical evaluation are time-sensitive. Do not wait for the end of the shift.
Patient preparation and identification (11 cards)
PHF-048 · Card 48 of 72Is a room number an acceptable second patient identifier?Show answer
No. The Joint Commission's laboratory goal states that the patient's room number or physical location is not used as an identifier.
Why: A room identifies a location, not a person. The same room can hold different patients.
PHF-049 · Card 49 of 72Which identifiers does The Joint Commission name as acceptable?Show answer
The individual's name, an assigned identification number, a telephone number, or another person-specific identifier. At least two are used when collecting blood samples and other specimens for clinical testing.
Why: The test is in the phrase "person-specific." It has to belong to the person, not to the bed or the chart rack.
PHF-050 · Card 50 of 72When and where do you label the tubes?Show answer
Immediately after collection, in the presence of the patient. Containers used for blood and other specimens are labelled at the patient, not later.
Why: Stepping into the hallway to label creates an opportunity to switch specimens between patients. A mix-up may escape later checks; establish the patient-to-specimen link at collection.
PHF-051 · Card 51 of 72The patient states a date of birth that does not match the requisition. What do you do?Show answer
Stop and resolve the discrepancy before collecting anything.
Why: The identifier check is not a formality you complete and move past. A perfectly collected tube from the wrong person is worse than no tube.
PHF-052 · Card 52 of 72An unlabelled tube turns up on your tray. Can you label it from the requisition next to it?Show answer
No. The link between specimen and patient is made at the patient; a requisition on a tray does not prove which patient this tube came from. Follow your laboratory's identification and recollection policy.
Why: Laboratories do have written clarification policies, and some situations are resolvable. Guessing is not one of the routes.
PHF-053 · Card 53 of 72Whose hand hygiene guidelines does the laboratory accreditation goal point to?Show answer
The current CDC hand hygiene guidelines, the current WHO guidelines, or both.
Why: Useful to know the goal names an external guideline rather than writing its own. The guideline can be updated without the goal changing.
PHF-054 · Card 54 of 72Can an adult able to consent refuse a routine blood draw even when it has been ordered?Show answer
Yes. The patient has a right to refuse a test at any time before the blood sampling.
Why: An order authorises the test. It does not consent to it on the patient's behalf.
PHF-055 · Card 55 of 72An adult able to consent refuses a routine blood draw. What next?Show answer
Do not proceed. Follow your facility's process for documenting and reporting the refusal so the ordering clinician knows.
Why: The important half is the second half. A refusal that nobody records becomes a missing result later.
PHF-056 · Card 56 of 72Does every blood test require fasting?Show answer
No. Preparation is set per test — some need fasting, some do not, and some have other requirements.
Why: One fasting rule applied to every order is a good way to send a patient home hungry for no reason, or to collect a specimen that cannot be interpreted.
PHF-057 · Card 57 of 72A patient was told to fast and ate breakfast anyway. Do you collect and say nothing?Show answer
No. Record what actually happened and clarify the plan with the responsible clinician or the laboratory.
Why: Preparation changes interpretation, so the person reading the result needs to know. Whether to collect, delay, or cancel must be clarified with the responsible clinician or laboratory rather than assumed.
PHF-058 · Card 58 of 72A colleague asks about an identifiable patient's results while you are both in a public lift. What do you do?Show answer
Move the conversation to an appropriate private setting.
Why: Care-team communication is permitted and necessary. HHS requires reasonable safeguards and permits some incidental disclosures; that is not a reason to hold an avoidable identifiable discussion in a public lift.
Blood and circulation basics (6 cards)
PHF-059 · Card 59 of 72What is the difference between serum and plasma?Show answer
Plasma is the liquid separated from anticoagulated blood, so it retains fibrinogen. Serum is the liquid separated after blood has clotted — fibrinogen has been used to form the clot.
Why: An anticoagulant tube initially holds whole blood; centrifugation separates its plasma from the cells. Do not define serum as "blood without cells" and stop there; that also describes separated plasma.
PHF-060 · Card 60 of 72What is a red blood cell's main job?Show answer
Carrying oxygen, using haemoglobin.
Why: Tie the cell to the function rather than memorising the abbreviation. It makes tube-to-test questions easier.
PHF-061 · Card 61 of 72What do white blood cells broadly do?Show answer
Help the body fight infection and disease.
Why: They are not the oxygen carriers. A count of them tells a very different clinical story.
PHF-062 · Card 62 of 72What do platelets do?Show answer
Help form clots to limit bleeding.
Why: Platelets are cell fragments that participate in clot formation. They are not the oxygen-carrying red cells or the infection-fighting white cells.
PHF-063 · Card 63 of 72What actually distinguishes an artery from a vein?Show answer
Direction. Arteries carry blood away from the heart; veins return it to the heart.
Why: Do not define them as oxygenated versus deoxygenated. The pulmonary circulation reverses that shortcut, and questions know it.
PHF-064 · Card 64 of 72What is hemolysis, and why does the laboratory care?Show answer
Damage or rupture of red blood cells, which releases their contents into the surrounding liquid. Labcorp does not accept severely hemolysed samples for coagulation testing, and squeezing hard during a capillary collection makes hemolysis more likely.
Why: Hemolysis is not the same as clotting. Clotting forms a clot — intended in a serum tube, unwanted in an anticoagulated specimen. Hemolysis is red cells being broken.
Specimen handling and special collections (8 cards)
PHF-065 · Card 65 of 72Before you inoculate blood culture bottles, what happens to the bottle tops?Show answer
Disinfect the rubber septum on each bottle with 70% isopropyl alcohol.
Why: The bottle top is a second contamination route. Skin antisepsis alone does not cover it.
PHF-066 · Card 66 of 72For an adult blood culture set, what is more important — volume or timing?Show answer
Volume. CDC states that the volume collected is most critical. Its example adult procedure uses 10 mL per bottle for a two-bottle, 20 mL set; its broader guidance describes 20–30 mL per adult set depending on the system. Follow the specific bottle and laboratory instructions, not one volume for every patient or bottle.
Why: Under-filled cultures can miss a bloodstream infection. Timing still matters, including collection before antibiotics when possible. These adult volumes are not paediatric instructions.
PHF-067 · Card 67 of 72Why does blood culture contamination matter to the patient, not just the laboratory?Show answer
A false positive from skin organisms can lead to unnecessary antibiotic therapy and prolonged hospitalisation.
Why: Collection quality is not a paperwork issue. It changes what happens to the person.
PHF-068 · Card 68 of 72What do you record at the time a blood culture is collected?Show answer
The exact time and date, the volume in each bottle, the anatomic site, the collection method, the person who collected it, and the facility location where it was collected.
Why: Those details support traceability and interpretation of the result. Site and method alone do not prove whether an organism is a contaminant.
PHF-069 · Card 69 of 72Why is not touching the prepared site especially important for a blood culture?Show answer
Touching disinfected skin can reintroduce organisms where the needle will enter. Skin organisms are a recognized source of false-positive blood cultures.
Why: WHO's instruction to avoid touching the prepared site applies to routine venipuncture too. For cultures, preventing contamination helps avoid an unnecessary treatment decision.
PHF-070 · Card 70 of 72What must a written critical-result procedure define?Show answer
What counts as a critical result, by whom and to whom it is reported, and the acceptable length of time between a result becoming available and being reported. The procedure also addresses documenting the communication, and the organisation has to evaluate whether reporting is actually timely.
Why: "Call it right away" is not a procedure. Define the result, the reporting route and the time limit, and document the communication.
PHF-071 · Card 71 of 72What has to travel with a specimen into an aliquot tube?Show answer
The same patient identification as the primary specimen, plus whatever the laboratory requires about specimen type and additive.
Why: An aliquot is a portion transferred into another container. That transfer must preserve the patient-to-specimen link; a new container is not a new identity.
PHF-072 · Card 72 of 72How long does a serum tube need before it is centrifuged?Show answer
Long enough for clotting to finish, and that depends on the tube. BD's guide lists 30 minutes for its gold serum-separator tubes and 60 minutes for its red serum tubes, including the listed plastic clot-activator tubes. Use the particular tube's instructions and the test's processing requirements.
Why: Spinning before clotting is complete can leave fibrin in the separated serum. Two tubes that both give serum, two different clot times — check the tube, not the colour family.
How to use these cards
Answer before you open the card. Then read the whole back, not just the words you happened to remember — the "Why" line is doing most of the teaching.
When you miss a card's key point or its condition, note its PHF number and come back to that smaller set rather than running the whole deck again. A note that you remembered a card is your own recall judgment, not a score or a prediction that you will pass.
Two practical suggestions. When you are learning a topic for the first time, work through that topic in order, because several cards build on the one before. When you are reviewing topics you already know, try mixing them so the preceding card does not give away the next answer. That is a study suggestion, not a prescription, and there is no daily card quota anywhere on this page.
Which exam are these phlebotomy flashcards for?
These are general United States phlebotomy fundamentals. They are not an official deck for any one certification, and a focused deck cannot replace the content outline your certifying body publishes — that outline is your coverage checklist, and this deck is bounded on purpose.
Certified Phlebotomy Technician (CPT), National Healthcareer Association. The current exam version went live on January 7, 2026. The test plan is based on a job analysis completed in 2024, and it specifies 100 scored items plus 20 unscored pretest items in two hours. NHA test plan, page 1 · NHA exam-version announcement.
| NHA CPT domain | Scored items | Share of scored items |
|---|---|---|
| Safety and Compliance | 26 | 26% |
| Patient Preparation | 20 | 20% |
| Routine Blood Collections | 28 | 28% |
| Special Collections | 12 | 12% |
| Processing | 14 | 14% |
| Total scored | 100 | 100% |
Two things worth knowing about that table. Capillary collection sits inside Routine Blood Collections on this plan — it is not a separate domain, however it is grouped in older study material. And these are the exam's allocations, not this deck's. Our seven topics are study groupings chosen to make the cards learnable; the card counts are ours and they do not mirror the official weights. NHA test plan, page 5, tasks 3O and 3P.
Phlebotomy Technician, PBT(ASCP) and PBT(ASCPi), ASCP Board of Certification. The content guideline was revised on September 25, 2025. It describes 80 multiple-choice questions with one best answer, in two hours, delivered by computer adaptive testing, across six content areas: Circulatory System 5–10%; Specimen Collection 45–50%; Specimen Handling, Transport, and Processing 15–20%; Waived and Point-of-Care Testing (POCT) 5–10%; Non-Blood Specimens 5–10%; Laboratory Operations 15–20%. The guideline covers both credentials; this deck's workplace and regulatory examples remain United States-specific.
One detail from that guideline is worth carrying into the exam room: results and reference ranges are presented in both conventional and SI units. If you see an unfamiliar unit beside a familiar one, that is the format, not a trick. ASCP content guideline, page 2.
Other credentials. The National Center for Competency Testing offers the Phlebotomy Technician (NCPT), and American Medical Technologists offers the Registered Phlebotomy Technician (RPT). Each publishes its own outline. We have not reproduced their exam specifications here, because a deck is not the right place to learn administration rules — go to the source for yours.
One boundary that matters more than the blueprint. Nothing on this page establishes eligibility, authorises you to collect blood, or answers a particular state's application requirements. For that, ask the authority in the state where you intend to work.
And the honest limit on this deck. Working through all 72 cards means you have reviewed this set, not demonstrated mastery. It does not mean you are ready for an exam, and it certainly does not mean you are clinically competent. More is on every official outline than a focused deck covers.
Check the version behind your study material
An older document code and an incorrect collection answer are different problems. Use the exact document and edition to check which one you are dealing with.
| Earlier reference | Current reference checked September 14, 2026 | What to check |
|---|---|---|
| CLSI GP41, 7th edition (2017) — venous collection | CLSI PRE02, 8th edition, published February 13, 2025 | PRE02-Ed8 replaces GP41-Ed7. The public change summary is not the full standard; it does not establish that every collection instruction is unchanged. |
| CLSI GP33, 2nd edition (2019) — patient and specimen identification | CLSI PRE01, 1st edition, published March 8, 2024 | PRE01 replaces GP33-Ed2. Its public change list includes obtaining patient consent in the patient-identification process. |
| CLSI GP42-A6 (2008) — capillary collection | CLSI GP42, 7th edition, published September 16, 2020 | The current capillary reference remains GP42. The public change list includes puncture-site identification and positioning instructions. |
| An NHA CPT test plan from before 2026 | Test plan based on the 2024 job analysis; exam version live from January 7, 2026 | Use the five current domain names and item counts above for this exam version. |
| An older ASCP PBT content guideline | Guideline revised September 25, 2025 | Compare its six content areas and percentage ranges with the document you are using. |
The CLSI links above establish the document names, editions and public change summaries. They are not a review of the full standards. For the venous sequence used in this deck, CLSI's publicly readable order of draw article supplies the six groups and the pre-citrate exceptions. A citation to the older GP41 name does not, by itself, prove that a particular collection answer is wrong; check the answer against its supporting source.
Why two trustworthy sources give different inversion counts
The number depends on the tube and its manufacturer. These are the counts in the two named manufacturer guides, not one rule for every tube with the same closure colour.
| Tube | BD Vacutainer: inversions | Greiner Bio-One VACUETTE: inversions |
|---|---|---|
| Sodium citrate (light blue) | 3–4 | 4 |
| Serum, clot activator (BD plastic red / gold) | 5 | 5–10 |
| Heparin (green) | 8 | 5–10 |
| EDTA (lavender) | 8 | 8–10 |
| Glycolytic inhibitor (gray) | 8 | 5–10 |
Sources: BD Vacutainer tube guide, page 1 · Greiner Bio-One order of draw, page 2. The serum row refers to clot-activator tubes; BD's silicone-coated glass red tube is a separate zero-inversion entry, not the plastic red tube in this row.
Inversion counts are manufacturer specifications for that manufacturer's tubes. They are not a universal fact about the colour lavender. Your instructor's chart and your textbook's chart can both be correct and still disagree, because they are describing different products.
So learn the reason rather than one digit. Inverting mixes the additive through the blood. Inadequate mixing can leave an anticoagulated specimen with clots or a clot-activator specimen incompletely clotted. Shaking instead of gently inverting can cause hemolysis. On the bench, use the current instructions for the tubes your laboratory actually stocks. Greiner Bio-One handling notes, page 2 · BD guide, inversion footnote.
The same logic runs through several cards above. A red cap does not tell you whether there is a clot activator in the tube. A royal-blue cap does not tell you whether the tube holds a clot activator or K2EDTA. A green cap does not tell you whether the heparin is lithium or sodium. Read the tube.
What this deck is, and what it isn't
It is: 72 original cards, written from published regulations, government clinical guidance, exam outlines, manufacturer specifications, and the other named technical references. Every card names its source and links to it. Free, complete on this page, with no account, no email, and no separate test you have to take first.
It isn't: official material from any certifying body, or real, recalled, leaked, or reconstructed protected exam content. It isn't a readiness score or a pass prediction. And it isn't a full course: there is no non-blood specimen curriculum here, no donor-services module, no waived-testing quality-control course, no paediatric volume tables, no lancet depth settings, no intravenous line protocols. Use your official exam outline to identify what else belongs in your preparation.
A flashcard deck teaches recall and reasoning. It cannot demonstrate that you can find a vein or collect a specimen safely. Those are supervised-training tasks, not recall scores.
Sources and verification
By the Castleport Test Prep Editorial Team
Every consequential answer above is tied to a document we opened. Source checking is not clinical review. For an actual collection, the current instructions for the tubes in your hand and your laboratory's own procedure govern.
Exam outlines
NHA CPT Test Plan · NHA CPT exam-version announcement · ASCP BOC PBT Examination Content Guideline · NCCT, Phlebotomy Technician (NCPT) · AMT, Registered Phlebotomy Technician (RPT)
Standards and their current designations
CLSI, Order of Blood Draw Tubes and Additives · CLSI PRE02, Collection of Diagnostic Venous Blood Specimens, 8th edition · CLSI PRE01, Patient and Laboratory Specimen Identification Processes, 1st edition · CLSI GP42, Collection of Capillary Blood Specimens, 7th edition
Regulation and accreditation
29 CFR 1910.1030, Bloodborne pathogens · 42 CFR 493.1232, Specimen identification and integrity · The Joint Commission, 2026 Laboratory National Patient Safety Goals
Government clinical and laboratory guidance
CDC, Standard Precautions for All Patient Care · CDC, Hand Hygiene for Healthcare Workers · CDC/NIOSH, Bloodborne Infectious Disease Risk Factors · CDC, Collect Adult Blood Culture Sets · CDC, Prevent Adult Blood Culture Contamination · WHO Guidelines on Drawing Blood, chapter 2 · WHO Guidelines on Drawing Blood, chapter 7 · WHO Best Practices for Injections and Related Procedures Toolkit, blood collection · WHO Guidelines on Drawing Blood, chapter 3 · MedlinePlus, How to Prepare for a Lab Test · MedlinePlus, Complete Blood Count (CBC) · NHLBI, How Blood Flows through the Heart · HHS, Incidental Uses and Disclosures
Laboratory and manufacturer technical references
Labcorp, Blood Specimens: Coagulation · Labcorp, Abnormal Screening Results Guidance · Labcorp, Blood Specimens: Chemistry and Hematology · Labcorp, Lithium test 007708 · BD Vacutainer Venous Blood Collection Tube Guide · BD trace-element tube 368380 · BD trace-element tube 368381 · BD Microtainer, order-of-draw FAQ · Greiner Bio-One, VACUETTE Order of Draw · Greiner Bio-One, Evaluation of VACUETTE 9NC Coagulation Sodium Citrate 3.2% Tubes · DynaLIFE, Phlebotomy—Collecting Blood by Venipuncture
Additional guidelines and primary research
AACC/ADA, Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus · Cornes, Ford and Gama, EDTA contamination study · Krleza and colleagues, Capillary blood sampling recommendations
Manufacturer and laboratory references describe specific products and specific laboratories. They are named to make a principle concrete, not to recommend a product or a testing company.
A note on how this page was made. Castleport Test Prep writes with AI assistance and human editorial direction. The cards are original to us, and the source for each one is named on the card so you can check any answer against the document rather than taking ours for it.
Independence. Castleport Test Prep is an independent exam prep publisher. We are not affiliated with, endorsed by, or approved by the National Healthcareer Association, the American Society for Clinical Pathology Board of Certification, the National Center for Competency Testing, American Medical Technologists, the Clinical and Laboratory Standards Institute, The Joint Commission, or any testing vendor or licensing board. These are original, unofficial study cards, not official exam questions. Exam, credential, and standard names identify their subjects, and trademarks belong to their respective owners.
Last verified: September 14, 2026 — the identified exam outlines, regulations, clinical and laboratory principles, and manufacturer references used on this page. CLSI edition details were checked against its public catalog; the full standards were not reviewed.