Phlebotomy Practice Test
This is a free 15-question phlebotomy sampler, written by the StudyPDF team. It covers the order of draw and why it exists, tube additives and what each one does, the veins of the antecubital fossa, patient identification, complications such as hemolysis and hematoma, capillary collection, special handling and sharps safety, mixing multiple choice, select all that apply and fill in the blank. Answer all 15 questions, then check your score and read the explanation for every question.
Following the standard order of draw, which tube is collected immediately after the light blue sodium citrate tube?
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All 15 questions at a glance
Prefer to read before you play? Every question in the sampler is listed below. Answers and explanations stay collapsed until you open them.
1. Following the standard order of draw, which tube is collected immediately after the light blue sodium citrate tube?
- A. The lavender EDTA tube
- B. The gray sodium fluoride tube
- C. The red or gold serum tube
- D. The green heparin tube
Show answer and explanation
Answer: C. The red or gold serum tube
The standard sequence is blood cultures first, then the light blue citrate tube, then serum tubes with or without a gel separator, then heparin, then EDTA, then the glycolytic inhibitor tube. The citrate tube comes early because coagulation testing depends on an exact ratio of blood to additive, and it must be filled to the mark for that ratio to hold.
2. Why does the order of draw exist?
- A. To keep additive from one tube from carrying over into the next through the needle
- B. To keep the total time of the draw under a fixed limit
- C. To fill the largest tubes while the vein is still full
- D. To match the order in which the laboratory runs the tests
Show answer and explanation
Answer: A. To keep additive from one tube from carrying over into the next through the needle
Blood in the needle and the holder can carry a trace of additive backward into the following tube, and a trace is enough to ruin a result. EDTA carried into a chemistry tube is the classic example, because the potassium in the salt makes potassium read falsely high and the chelated calcium makes calcium read falsely low.
3. Complete the sentence.
The lavender top tube contains _____, which stops the specimen from clotting by binding _____.
Options for blank 1: sodium citrate, EDTA, lithium heparin, sodium fluoride
Options for blank 2: calcium, potassium, sodium, iron
Show answer and explanation
Answer: EDTA, calcium
EDTA binds calcium, and the clotting cascade cannot run without it. It also preserves cell shape better than the other anticoagulants, which is why it is the tube for a complete blood count and a blood smear. The tube has to be filled to the marked volume, because leftover EDTA in an underfilled tube shrinks the red cells and skews the count.
4. In the antecubital fossa, which vein is usually the first choice for venipuncture?
- A. The cephalic vein
- B. The median cubital vein
- C. The basilic vein
- D. The brachial artery
Show answer and explanation
Answer: B. The median cubital vein
The median cubital vein sits toward the middle of the antecubital fossa, is generally large and well anchored so it rolls less, and lies farthest from the major nerve and artery. The cephalic vein on the thumb side is the usual second choice. Vein patterns differ from person to person, so palpate first rather than assuming a textbook layout.
5. Why is the basilic vein the last choice among the antecubital veins?
- A. It is too small to accept a standard needle
- B. It collapses as soon as the tourniquet is released
- C. It carries arterial blood rather than venous blood
- D. It lies close to the brachial artery and the median nerve
Show answer and explanation
Answer: D. It lies close to the brachial artery and the median nerve
The basilic vein runs on the little finger side of the arm, and the brachial artery and the median nerve sit just under it. Puncturing either is the reason this vein is used only when the others are unavailable. It is also less anchored in the tissue, so it tends to roll away from the needle.
6. Which of the following make hemolysis more likely?
Select all that apply.
- A. Drawing through a needle that is too small for the vacuum of the tube
- B. Pushing blood from a syringe through the tube stopper under pressure
- C. Shaking the tubes hard instead of inverting them gently
- D. Letting the alcohol dry fully before the puncture
- E. Filling each tube to the volume the vacuum draws
Show answer and explanation
Answer: A. Drawing through a needle that is too small for the vacuum of the tube, B. Pushing blood from a syringe through the tube stopper under pressure, C. Shaking the tubes hard instead of inverting them gently
Hemolysis is red cells breaking open, and it happens when the cells are forced through too narrow an opening, pushed under pressure, or shaken. It matters because the contents of the cells spill into the plasma, so potassium, LDH, magnesium and phosphate all read falsely high, and a visibly pink or red sample is usually rejected. Letting alcohol dry and filling tubes properly both reduce the risk rather than raise it.
7. An inpatient is scheduled for a draw. Which identification step meets the standard?
- A. Ask the patient whether they are Mrs. Alvarez and draw if they say yes
- B. Match the name posted on the door of the room to the requisition
- C. Ask the patient to state their full name and date of birth, then compare both with the armband and the requisition
- D. Confirm the patient's name with the nurse assigned to the room
Show answer and explanation
Answer: C. Ask the patient to state their full name and date of birth, then compare both with the armband and the requisition
Identification has to be active, using two identifiers the patient supplies rather than ones you offer. A yes or no question invites the wrong answer from someone who is drowsy, hard of hearing or confused. Room numbers and bed numbers are never identifiers, because patients get moved.
8. Complete the sentence.
The gray top tube contains _____, which slows glycolysis so that the _____ result does not drift downward while the specimen waits to be tested.
Options for blank 1: EDTA, sodium citrate, sodium fluoride, a clot activator
Options for blank 2: potassium, glucose, hemoglobin, albumin
Show answer and explanation
Answer: sodium fluoride, glucose
Red cells keep consuming glucose after the blood leaves the arm, so an untreated sample reads lower the longer it sits. Sodium fluoride blocks an enzyme in the glycolytic pathway and holds the value steady, which is why this tube is used for glucose and for alcohol testing. It is usually paired with potassium oxalate, which handles the anticoagulation.
9. Which anticoagulant prevents clotting by blocking thrombin rather than by binding calcium?
- A. Sodium citrate
- B. EDTA
- C. Potassium oxalate
- D. Heparin
Show answer and explanation
Answer: D. Heparin
Heparin works further along the cascade. It boosts antithrombin, which shuts down thrombin and factor Xa, so fibrin never forms. Citrate, EDTA and oxalate all work the other way, by tying up the calcium the cascade needs. Because heparin leaves the sample's chemistry closest to untouched, heparin tubes are common for chemistry panels.
10. During a draw the patient reports a sharp, shooting, electric pain running down the forearm. What should the phlebotomist do?
- A. Release the tourniquet, withdraw the needle right away, and stop the draw
- B. Continue, since brief pain is expected during venipuncture
- C. Rotate the needle to a shallower angle and continue
- D. Loosen the tourniquet and collect the remaining tubes quickly
Show answer and explanation
Answer: A. Release the tourniquet, withdraw the needle right away, and stop the draw
Shooting or electric pain, tingling or numbness suggests the needle is near or in a nerve, and that is one of the few injuries from a blood draw that can last. The response is to stop rather than to reposition. Ordinary venipuncture stings briefly at the puncture and then settles, which is different from pain that travels down the limb.
11. Which of these are correct sharps and infection control practices during venipuncture?
Select all that apply.
- A. Activate the needle safety device as soon as the needle leaves the arm
- B. Discard the needle and the tube holder together as a single unit
- C. Recap the needle with two hands before disposing of it
- D. Perform hand hygiene and put on clean gloves before every patient
- E. Fill the sharps container to the very top before it is replaced
Show answer and explanation
Answer: A. Activate the needle safety device as soon as the needle leaves the arm, B. Discard the needle and the tube holder together as a single unit, D. Perform hand hygiene and put on clean gloves before every patient
Most needlestick injuries happen between the arm and the container, so the safety device goes on immediately and the needle is not handled again. Recapping with two hands points a contaminated needle at your own fingers. An overfilled sharps container is a puncture hazard on its own, which is why containers are replaced at the marked fill line rather than when they stop closing.
12. A swelling appears at the site during a draw and the blood flow slows. What is the most likely cause?
- A. The tourniquet was applied too loosely
- B. The needle went through the far wall of the vein
- C. The additive in the tube had expired
- D. The patient's arm was held above the level of the heart
Show answer and explanation
Answer: B. The needle went through the far wall of the vein
That swelling is a hematoma, blood leaking out of the vessel into the surrounding tissue. It usually means the needle passed through the back wall, or that the bevel is only partly in the vein, or that a nearby vessel was nicked. Release the tourniquet, remove the needle and hold firm pressure, and do not try to save the draw by pushing the needle deeper.
13. Which statements about capillary, or dermal, collection are correct?
Select all that apply.
- A. The first drop is wiped away because it is diluted with tissue fluid
- B. The EDTA tube is filled before the other additive tubes
- C. On an infant, the puncture is made on the medial or lateral plantar surface of the heel
- D. Repeated hard squeezing of the site is used to speed up the flow
- E. A capillary sample is the preferred specimen for blood cultures
Show answer and explanation
Answer: A. The first drop is wiped away because it is diluted with tissue fluid, B. The EDTA tube is filled before the other additive tubes, C. On an infant, the puncture is made on the medial or lateral plantar surface of the heel
Capillary collection reverses the venipuncture order because platelets start clumping at the puncture within seconds, so the hematology tube is filled first. Hard squeezing, sometimes called milking, forces tissue fluid into the sample and breaks red cells. On an infant the puncture stays on the sides of the plantar surface to keep away from the heel bone. Blood cultures need a larger sterile volume than a fingerstick can give.
14. Complete the sentence.
A specimen collected for _____ is wrapped in foil or collected in an amber tube, because that substance breaks down when the sample sits in the light.
Options for blank 1: potassium, glucose, bilirubin, hemoglobin
Show answer and explanation
Answer: bilirubin
Bilirubin is light sensitive, so even a short spell on a sunny counter can drop the value and make a jaundiced newborn look better than they are. Light protection is one of three special handling rules worth knowing together. Some specimens travel chilled, some have to stay near body temperature until they are processed, and the requisition or the laboratory manual says which.
15. When should a blood collection tube be labeled?
- A. Back in the laboratory, once the specimen has been checked in
- B. Before the draw, so the tube is ready when it fills
- C. At the end of the round, together with the rest of the batch
- D. At the patient's side, right after the tubes are filled and before leaving
Show answer and explanation
Answer: D. At the patient's side, right after the tubes are filled and before leaving
Labeling at the bedside, with the patient still in front of you, is what keeps a tube tied to the right person. Prelabeled tubes can end up on the wrong patient, and labeling later relies on memory. The label carries the patient's full name, a second unique identifier, and the date and time of collection, plus whatever else your facility requires, such as the collector's initials.
What a phlebotomy exam actually covers
There is no single national phlebotomy exam. Several organizations certify phlebotomists, among them the National Healthcareer Association, the American Society for Clinical Pathology, American Medical Technologists and the National Center for Competency Testing. Each one sets its own question count, time limit, passing score, eligibility routes and recertification rules, and those details get revised, so the only reliable source for them is the current candidate handbook of the body you are testing with. Some states also set their own license or certification requirement for drawing blood, on top of any national certificate. Those rules are set state by state, not nationally, so check your own state's health department as well.
What the outlines have in common is the work itself. Nearly all of them expect you to know the order of draw and the reason behind it, which additive sits in which tube and how it works, the veins of the antecubital fossa and how to choose a site, how to identify a patient and label a specimen, the common complications and what causes each, capillary collection and how it differs from venipuncture, special handling such as chilling and light protection, and infection control and sharps safety. Most also test a little specimen processing, professionalism and patient privacy.
Two things carry more weight than newcomers expect. The first is order. Exams ask what you do first, what comes next and what you do the moment something goes wrong, because in this job the sequence is the skill. The second is safety, both yours and the patient's, so expect questions on needle devices, sharps disposal and the situations where you stop a draw rather than finish it.
How to use this sampler
These 15 questions lean on the why rather than the naming. They ask what an additive actually does to the blood, why the tubes come off the needle in a fixed order, why the median cubital vein is chosen ahead of the basilic, and what a swelling or a shooting pain during a draw is telling you. That reasoning is what makes the memorized lists stick, because a rule you can explain is one you will not scramble under time pressure.
Take it in one sitting without notes, then read the explanation for every question, including the ones you got right. Treat a wrong answer as a topic rather than a fact. If you missed the order of draw question and the additive question, study tubes and additives together as one table, since they are the same knowledge asked from two directions.
One thing to be clear about. This is exam practice, not medical guidance. Nothing on this page tells you how to care for a patient. When you are collecting for real, follow your employer's written procedure, your instructor or supervisor, and the manufacturer's instructions for the tubes and safety devices you actually use.
How StudyPDF builds full practice tests from your own materials
Fifteen questions can show you where you are shaky. They cannot get you ready on their own, and a generic bank rarely matches what your own program or your employer's competency checklist emphasizes.
StudyPDF works from your material instead. You upload your phlebotomy textbook, your lab manual or the handouts your program gave you, and Bo, the study agent, builds full-length practice tests from those exact pages. Every question is grounded in your material, and every explanation cites where the answer comes from, so you can go straight to the source when something looks off. You can regenerate fresh tests as often as you like, narrow them to one area such as order of draw or complications, and track which concepts you keep missing.
You do not have to upload anything to start. If you have no file at hand, name a topic instead, for example tube additives or capillary collection, and Bo writes a practice test from that. Starting is free.
Written by the StudyPDF team. Last updated 2026-08-19.