Phlebotomy Processing Practice Test

25 practice questions

Choose an answer, then check it under Show answer.

1. Question 1 of 25Hard

   A waived analyzer's instructions state it must be operated between 59 F and 86 F (15 C and 30 C). On a hot day, the clinic's testing room thermometer reads 91 F (about 33 C). What should the phlebotomist do?

   1. AA. Test patients anyway, since the room is only a little too warm
   2. BB. Test patients and add a comment noting the room temperature
   3. CC. Test only where conditions are within range and report the issue
   4. DD. Run the controls first and, if they pass, test patients in that room
   Show answer to question 1

   Answer: C. Test only where conditions are within range and report the issue

   The manufacturer's operating range is a testing requirement; outside it, reagents and electronics may not perform correctly. Patient testing is done only where conditions are within range, and the problem is reported so it can be corrected.

   Why the other options are wrong

   • AAny temperature outside the stated range can make results unreliable, even by a few degrees.
   • BA comment does not make results valid when the test was run outside the manufacturer's conditions.
   • DPassing controls do not override the manufacturer's operating limits for patient testing.

2. Question 2 of 25Medium

   After centrifuging a gold-top tube drawn for a potassium level at an outpatient draw station, the processor sees bright red serum. What should the processor do?

   1. AA. Centrifuge the tube again so the red color settles out of the serum
   2. BB. Pour off only the top layer of serum, which is less affected
   3. CC. Reject it per hemolysis policy and request a new specimen
   4. DD. Release the potassium result, since the analyzer measured it
   Show answer to question 2

   Answer: C. Reject it per hemolysis policy and request a new specimen

   Bright red serum after centrifugation means the specimen is grossly hemolyzed. Ruptured red cells release potassium, which falsely raises the result, so the specimen is rejected per the laboratory's hemolysis policy and recollected.

   Why the other options are wrong

   • AHemoglobin released from ruptured cells is dissolved in the serum, so spinning again cannot remove it.
   • BThe released potassium and hemoglobin are mixed throughout the serum, so no layer is unaffected.
   • DA measured value is still falsely high when cells have ruptured, and reporting it could lead to unneeded treatment.

3. Question 3 of 25Easy

   A laboratory has kept a rack of blood specimens in the refrigerator for the retention period set by its policy, and they are no longer needed. How should the tubes be discarded?

   1. AA. Empty them into the sink and recycle the plastic tubes
   2. BB. Place the capped tubes in a sealed bag in the regular trash
   3. CC. Rinse the tubes with bleach and put them in the recycling bin
   4. DD. Place the capped tubes in a biohazard waste container
   Show answer to question 3

   Answer: D. Place the capped tubes in a biohazard waste container

   Blood specimen tubes are regulated medical waste. When the retention period ends, the capped tubes are discarded in a labeled biohazard waste container according to facility policy and local regulations.

   Why the other options are wrong

   • AEmptying tubes into a sink risks splashes, and contaminated tubes cannot go into recycling.
   • BBlood-filled tubes are biohazardous waste and cannot go into the regular trash.
   • CRinsing used tubes risks splashes and exposure, and the tubes still cannot be recycled.

4. Question 4 of 25Medium

   A correctly performed potassium test is filed in the wrong patient's medical record. In which phase of the testing process did this error occur?

   1. AA. Pre-analytical, before the specimen is tested
   2. BB. Analytical, while the specimen is being tested
   3. CC. Post-analytical, after the result is produced
   4. DD. Calibration, while the analyzer is being adjusted
   Show answer to question 4

   Answer: C. Post-analytical, after the result is produced

   Testing has three phases: pre-analytical (ordering through specimen preparation), analytical (the test itself), and post-analytical (reporting and filing results). A correct result filed in the wrong record is a post-analytical error.

   Why the other options are wrong

   • APre-analytical errors happen before testing, such as misidentification at collection or improper handling.
   • BThe test itself was performed correctly, so the analytical phase was not where the error happened.
   • DCalibration is part of the analytical phase rather than a separate phase, and the result itself was accurate.

5. Question 5 of 25Easy

   When a phlebotomist reports a critical point-of-care result by telephone, what should the person receiving the result be asked to do?

   1. AA. Write the result down and fax a copy back to the laboratory
   2. BB. Call the patient now and explain what the result means
   3. CC. Send an email later confirming that the result was received
   4. DD. Read the result and patient identifiers back to confirm them
   Show answer to question 5

   Answer: D. Read the result and patient identifiers back to confirm them

   Read-back, in which the receiver repeats the result and patient identifiers and the caller confirms them, catches errors in verbal communication. The caller then documents the notification per policy.

   Why the other options are wrong

   • AFaxing back adds delay, while read-back during the call confirms the information immediately.
   • BDeciding how and when to tell the patient is the provider's role, not something the phlebotomist directs.
   • CA later email does not confirm the result was understood correctly during the call and may not be read promptly.

6. Question 6 of 25Hard

   While preparing to collect specimens from a patient enrolled in a clinical trial, a phlebotomist finds that the study kit is missing one of the required tubes. What is the best action?

   1. AA. Substitute a stock tube with the same stopper color
   2. BB. Contact the study coordinator before collecting
   3. CC. Collect the other tubes and draw the missing one at the next visit
   4. DD. Collect extra blood in a syringe to transfer later
   Show answer to question 6

   Answer: B. Contact the study coordinator before collecting

   Study kits contain the exact tubes, labels, and supplies the protocol requires. When something is missing, the phlebotomist contacts the study coordinator for direction before collecting rather than improvising.

   Why the other options are wrong

   • AA stock tube may differ in additive, volume, or manufacturer from what the protocol specifies.
   • CSkipping a required tube changes the study's specimen set, a decision only the study team can make under the protocol.
   • DHolding blood in a syringe for later transfer is not in the protocol and risks clotting and hemolysis.

7. Question 7 of 25Medium

   A phlebotomist pipettes plasma from a patient's primary tube into an aliquot tube that will be sent to a reference laboratory. How should the aliquot tube be labeled?

   1. AA. With the patient's name only, since the primary tube has the full label
   2. BB. With the patient's name and room number from the requisition
   3. CC. With the test name and date, since the requisition is in the bag
   4. DD. With the same identifiers as the primary tube and the specimen type
   Show answer to question 7

   Answer: D. With the same identifiers as the primary tube and the specimen type

   Each aliquot tube carries the same patient identifiers as the primary tube plus the specimen type, such as plasma. Once separated from the primary tube, an aliquot without full labeling cannot be traced to the patient.

   Why the other options are wrong

   • AA name alone is a single identifier, and every specimen container needs at least two.
   • BA room number is never an acceptable identifier, so this label has only one valid identifier.
   • CThe requisition can be separated from the tube, so the tube itself must carry the patient identifiers.

8. Question 8 of 25Easy

   Which group of tests requires the specimen to be protected from light?

   1. AA. Glucose, triglycerides, and other fasting tests
   2. BB. Cold agglutinins, cryoglobulins, and cryofibrinogen
   3. CC. Vitamin B12, folate, and beta carotene
   4. DD. Sodium, potassium, chloride, and carbon dioxide
   Show answer to question 8

   Answer: C. Vitamin B12, folate, and beta carotene

   Vitamin B12, folate, and beta carotene break down when exposed to light, which can falsely lower results. These specimens are collected in amber containers or wrapped in foil.

   Why the other options are wrong

   • AFasting tests depend on patient preparation, and glucose and triglycerides need no light protection.
   • BThese specimens must be kept at body temperature, which is a temperature requirement rather than light protection.
   • DThese electrolytes have no light-protection requirement.

9. Question 9 of 25Medium

   The laboratory manual states that a send-out test requires frozen serum. The phlebotomist has just collected a gold-top tube from a 62-year-old woman at an outpatient clinic. Which preparation is correct?

   1. AA. Freeze the whole tube at once so the cells stop changing the serum
   2. BB. Refrigerate the whole tube, then centrifuge it right before shipping
   3. CC. Let it clot, spin it, and freeze the serum in a labeled aliquot tube
   4. DD. Centrifuge it at once, then pour the serum into a tube to freeze
   Show answer to question 9

   Answer: C. Let it clot, spin it, and freeze the serum in a labeled aliquot tube

   The tube is allowed to clot completely and is centrifuged, and the serum is pipetted into a labeled aliquot tube that is then frozen. Freezing whole blood ruptures red cells, so only separated serum is frozen.

   Why the other options are wrong

   • AFreezing whole blood causes hemolysis, which makes the serum unsuitable for testing.
   • BThe test requires frozen serum, and refrigerated whole blood does not meet that requirement.
   • DSpinning before clotting is complete can leave fibrin in the serum, and serum is pipetted, never poured.

10. Question 10 of 25Medium

    Why is a lavender-top (EDTA) tube that contains a small clot rejected for a CBC?

    1. AA. The clot concentrates the red cells, so hemoglobin reads falsely high
    2. BB. A clot shows the tube needed to be centrifuged before testing
    3. CC. The clot releases extra EDTA, which destroys white blood cells
    4. DD. Cells and platelets caught in the clot make the counts falsely low
    Show answer to question 10

    Answer: D. Cells and platelets caught in the clot make the counts falsely low

    EDTA should keep the whole blood from clotting. When a clot forms, platelets and white blood cells are used up or trapped in it, so the counts are falsely low and the CBC is unreliable; the specimen is recollected.

    Why the other options are wrong

    • AClotting removes cells from the liquid portion rather than concentrating them, so counts tend to fall, not rise.
    • BCBC specimens are whole blood and are not centrifuged; a clot means the anticoagulant did not work, often from delayed or poor mixing.
    • CA clot does not release EDTA; the problem is that cells and platelets are trapped in the clot.

11. Question 11 of 25Hard

    A specimen for a forensic drug test arrives in processing with its tamper-evident seal torn and one transfer on the custody form unsigned. What is the best action?

    1. AA. Apply a new seal and ask the courier to sign the blank line
    2. BB. Process it normally, since the label matches the custody form
    3. CC. Document the problems as found and notify the supervisor
    4. DD. Return it to the courier to take back to the collection site
    Show answer to question 11

    Answer: C. Document the problems as found and notify the supervisor

    A torn seal and a missing signature break the chain of custody. The receiver neither repairs the record nor disposes of the specimen; the specimen and form are kept, the problems are documented exactly as found, and the supervisor decides under policy whether the specimen can be used.

    Why the other options are wrong

    • AResealing or adding signatures after the fact falsifies the custody record.
    • BA matching label does not fix a broken seal or a gap in custody.
    • DSending it away adds an undocumented transfer and leaves the problems unreported.

12. Question 12 of 25Hard

    After collecting a forensic blood specimen requested by law enforcement in an emergency department, a phlebotomist is called away to help with another patient before the courier arrives. What should be done with the specimen?

    1. AA. Leave it sealed on the counter with a note for the courier
    2. BB. Ask a coworker to keep an eye on it until the courier comes
    3. CC. Place it in the routine specimen rack with the other tubes for now
    4. DD. Lock it in secure storage and note the transfer on the form
    Show answer to question 12

    Answer: D. Lock it in secure storage and note the transfer on the form

    A chain-of-custody specimen must stay in the collector's possession or in secure, locked storage at all times, and any change in custody, including placement in storage, is recorded on the form.

    Why the other options are wrong

    • AAn unattended specimen on a counter is not secure and could be tampered with.
    • BAn unrecorded handoff to a coworker breaks the chain, because every change in custody must be documented.
    • CA routine rack is not secure and mixes the specimen with ordinary specimens.

13. Question 13 of 25Medium

    A phlebotomist on an inpatient unit needs to send three tubes to the laboratory through the pneumatic tube system. Which step is required before sending them?

    1. AA. Seal the tubes in a leakproof biohazard bag and latch the carrier
    2. BB. Wrap the tubes in the requisition so they do not rattle in transit
    3. CC. Loosen the stoppers slightly so pressure changes do not pop them
    4. DD. Tape the tubes together and set them directly in the carrier
    Show answer to question 13

    Answer: A. Seal the tubes in a leakproof biohazard bag and latch the carrier

    Specimens sent by pneumatic tube are sealed in a leakproof biohazard bag, with padding or inserts if the facility uses them, and the carrier is closed and latched so nothing can open or leak inside the system.

    Why the other options are wrong

    • BPaperwork wrapped around tubes would be contaminated by any leak; it belongs in the bag's outer pocket.
    • CStoppers stay fully closed, because loose stoppers can leak and contaminate the carrier and the system.
    • DTaped tubes without a sealed bag can still break or leak into the carrier and the tube system.

14. Question 14 of 25Medium

    A physician office holds only a CLIA Certificate of Waiver. Which test may its staff perform on site?

    1. AA. A microscopic exam of urine sediment
    2. BB. A Gram stain of a wound specimen
    3. CC. An ABO type and crossmatch for transfusion
    4. DD. A visually read urine dipstick test
    Show answer to question 14

    Answer: D. A visually read urine dipstick test

    A Certificate of Waiver permits only tests the FDA has categorized as waived, such as a visually read urine dipstick, and each must be performed exactly as the manufacturer directs.

    Why the other options are wrong

    • AMicroscopic urine sediment examination is provider-performed microscopy, which requires a different CLIA certificate.
    • BA Gram stain is not a waived test, so it cannot be performed under a Certificate of Waiver.
    • CBlood typing and crossmatching for transfusion is high-complexity testing done by a certified transfusion service.

15. Question 15 of 25Medium

    A 36-year-old woman's outpatient specimen was quantity not sufficient (QNS) for all the tests her provider ordered. She returns the phlebotomist's call. How should the phlebotomist explain the need for a new draw?

    1. AA. Say that more blood is needed to finish the tests, and offer a time
    2. BB. Say that the coworker who drew her blood did it incorrectly
    3. CC. Say that her first results were probably abnormal and need a recheck
    4. DD. Say that coming back is optional, since some tests are already done
    Show answer to question 15

    Answer: A. Say that more blood is needed to finish the tests, and offer a time

    The phlebotomist explains simply and honestly that the specimen did not have enough blood to complete the ordered tests, apologizes for the inconvenience, repeats any preparation instructions (such as fasting, if ordered), and schedules the new draw.

    Why the other options are wrong

    • BBlaming a coworker is unprofessional and does not help the patient; the explanation should be factual and respectful.
    • CSuggesting abnormal results is inaccurate, alarming, and outside the phlebotomist's role.
    • DWhether any test can be skipped is the ordering provider's decision, not the phlebotomist's.

16. Question 16 of 25Easy

    A phlebotomist prepares a box of patient specimens classified as Category B for shipment. Which mark identifies these contents on the outer package?

    1. AA. The UN3373 mark printed inside a diamond-shaped border
    2. BB. The UN2814 marking with a Division 6.2 infectious substance label
    3. CC. The UN1845 marking with the net weight of the dry ice
    4. DD. The words Exempt Human Specimen on the outer package
    Show answer to question 16

    Answer: A. The UN3373 mark printed inside a diamond-shaped border

    Category B specimens are identified by the UN3373 mark, a diamond-shaped border around the number, and the words Biological Substance, Category B must appear next to it on the outer package.

    Why the other options are wrong

    • BUN2814 with a Division 6.2 label identifies Category A infectious substances, which carry a much higher risk than routine patient specimens.
    • CUN1845 identifies dry ice used as a coolant, not the biological contents.
    • DThe Exempt Human Specimen marking is for specimens with minimal likelihood of pathogens, not Category B shipments.

17. Question 17 of 25Medium

    Before the first patient of the day, a phlebotomist in a physician office sees a 'calibration required' message on a waived point-of-care analyzer. What should the phlebotomist do?

    1. AA. Test patients first and then calibrate it at the end of the day
    2. BB. Calibrate it as the manufacturer directs before patient testing
    3. CC. Restart the analyzer to clear the message, then start testing
    4. DD. Test patients now but hold results until it is calibrated
    Show answer to question 17

    Answer: B. Calibrate it as the manufacturer directs before patient testing

    Calibration aligns an analyzer's measurements with standards of known value. When the device requires calibration, patient results cannot be trusted until it is calibrated as the manufacturer directs and the calibration is documented, with controls run per policy.

    Why the other options are wrong

    • AResults produced before calibration may be inaccurate, and patients could be treated based on wrong values.
    • CClearing the message does not calibrate the analyzer and may hide a real problem.
    • DResults from an uncalibrated analyzer cannot be reported, so testing first wastes specimens and delays care.

18. Question 18 of 25Easy

    After a light-blue-top tube is centrifuged, a thin whitish layer appears between the plasma and the packed red cells. What does this layer contain?

    1. AA. White blood cells and platelets
    2. BB. Fibrin strands from early clotting
    3. CC. Fat droplets from a recent meal
    4. DD. Hemoglobin from ruptured red cells
    Show answer to question 18

    Answer: A. White blood cells and platelets

    The thin whitish layer between the plasma and the packed red cells is the buffy coat, which contains white blood cells and platelets.

    Why the other options are wrong

    • BFibrin appears as strands or small clots in the specimen, not as an even layer above the red cells.
    • CFats from a meal make the plasma cloudy or milky and rise toward the top rather than forming this layer.
    • DHemoglobin from ruptured cells dissolves in the plasma and turns it pink or red; it does not form a white layer.

19. Question 19 of 25Medium

    An EDTA whole blood specimen collected for an automated hemogram is inverted only once immediately after collection. How will this processing error most likely affect the specimen?

    1. AA. Microclots will form, falsely lowering the automated platelet count.
    2. BB. The sample will hemolyze and turn dark red throughout the plasma layer.
    3. CC. Excess liquid anticoagulant will cause the red blood cells to swell and lyse.
    4. DD. The buffy coat will expand and falsely increase the hematocrit reading.
    Show answer to question 19

    Answer: A. Microclots will form, falsely lowering the automated platelet count.

    Inadequate mixing of whole blood collected with an anticoagulant leads to microclot formation, which consumes platelets and falsely decreases the automated platelet count. While rough shaking causes hemolysis, failing to invert the tube 8 to 10 times causes partial clotting rather than cell rupture.

20. Question 20 of 25Medium

    When a needle punctures a vein, which hemostasis event happens first?

    1. AA. Fibrin strands form a stable clot over the site
    2. BB. The vessel constricts to slow the flow of blood
    3. CC. Plasmin breaks down the fibrin in the clot
    4. DD. Platelets clump together to form a plug
    Show answer to question 20

    Answer: B. The vessel constricts to slow the flow of blood

    Hemostasis begins with the vascular phase: the injured vessel constricts to reduce blood flow. Platelets then adhere and form a plug, coagulation converts fibrinogen to fibrin to strengthen it, and fibrinolysis later dissolves the clot.

    Why the other options are wrong

    • AFibrin formation is the coagulation stage, which follows vessel constriction and the platelet plug.
    • CFibrinolysis by plasmin is the final stage, removing the clot after the vessel heals.
    • DThe platelet plug forms after the vessel constricts, as the second stage.

21. Question 21 of 25Hard

    A courier delivers a serum aliquot for a send-out test from a physician office. The test directory states the specimen must stay frozen until testing, but the aliquot arrives fully thawed. What should the processor do?

    1. AA. Refreeze it right away and send it to the reference laboratory
    2. BB. Reject it, notify the office, and request a new specimen
    3. CC. Refrigerate it and send it with a note that it arrived thawed
    4. DD. Send it as is, since the serum was already separated from cells
    Show answer to question 21

    Answer: B. Reject it, notify the office, and request a new specimen

    The specimen did not meet its stated transport requirement, so its results could be unreliable. It is rejected, the reason is documented, and the office is notified so a new specimen can be collected and the transport problem corrected.

    Why the other options are wrong

    • ARefreezing cannot undo changes that occurred while the specimen was thawed, and repeated freezing and thawing can damage some analytes.
    • CA note does not make an improperly transported specimen acceptable when the requirement says it must stay frozen.
    • DSeparating serum from cells does not replace the frozen requirement, because some analytes break down once thawed.

22. Question 22 of 25Hard

    A cryoglobulin specimen collected at a long-term care facility cooled to room temperature during a long courier route before the serum was separated. How is the result most likely affected?

    1. AA. Falsely low, since the proteins precipitate and stay with the clot
    2. BB. Falsely high, since cooling concentrates the proteins in the serum
    3. CC. Unaffected, as long as the serum is rewarmed before testing
    4. DD. Falsely high, since cooled red cells release extra proteins
    Show answer to question 22

    Answer: A. Falsely low, since the proteins precipitate and stay with the clot

    Cryoglobulins are proteins that precipitate when the specimen cools below body temperature. If cooling happens before separation, they are removed with the clot and the result is falsely low or negative, so the specimen is kept at 98.6 F (37 C) until separated.

    Why the other options are wrong

    • BCooling removes cryoglobulins from the serum rather than concentrating them.
    • CRewarming the serum cannot recover cryoglobulins that were already removed with the clot.
    • DRed cells do not release cryoglobulins; the error comes from proteins lost with the clot.

23. Question 23 of 25Hard

    At a family medicine clinic, a phlebotomist performs a CLIA-waived fingerstick glucose test on a 58-year-old man. The result is 42 mg/dL, below the clinic's critical limit of 50 mg/dL. What should the phlebotomist do first?

    1. AA. Record the result in the chart and go on to the next patient
    2. BB. Notify the provider at once per the critical value policy
    3. CC. Repeat the test several times before telling anyone about it
    4. DD. Tell the patient to eat something and come back for a recheck
    Show answer to question 23

    Answer: B. Notify the provider at once per the critical value policy

    A result beyond the facility's critical limit may signal a life-threatening condition, so it is reported directly to the provider right away under the critical value policy, and the notification is documented.

    Why the other options are wrong

    • ACharting alone alerts no one; a critical value requires immediate direct notification.
    • CRetesting several times delays care; the provider must be told promptly, and any repeat testing is done only as policy directs.
    • DSending the patient away is outside the phlebotomist's role and could leave a dangerously low glucose untreated.

24. Question 24 of 25Easy

    Which federal agency administers the CLIA program, including issuing certificates to laboratories?

    1. AA. Occupational Safety and Health Administration (OSHA)
    2. BB. Centers for Medicare & Medicaid Services (CMS)
    3. CC. National Institute for Occupational Safety and Health (NIOSH)
    4. DD. Food and Drug Administration (FDA)
    Show answer to question 24

    Answer: B. Centers for Medicare & Medicaid Services (CMS)

    CMS administers CLIA: it issues laboratory certificates, collects fees, and oversees inspections and enforcement. The FDA categorizes tests by complexity, and the CDC provides scientific and technical support.

    Why the other options are wrong

    • AOSHA enforces workplace safety rules, such as the Bloodborne Pathogens Standard, not laboratory certification.
    • CNIOSH researches and recommends ways to prevent work-related injury and illness; it does not certify laboratories.
    • DThe FDA categorizes tests by complexity, including waived status, but does not issue CLIA certificates.

25. Question 25 of 25Easy

    Which test is used to monitor a patient's warfarin therapy?

    1. AA. Activated partial thromboplastin time (aPTT)
    2. BB. Platelet count from a CBC
    3. CC. Prothrombin time with INR (PT/INR)
    4. DD. Fibrin degradation (D-dimer) level
    Show answer to question 25

    Answer: C. Prothrombin time with INR (PT/INR)

    Warfarin lowers the vitamin K-dependent clotting factors, and its effect is monitored with the prothrombin time, reported as an INR so results can be compared between laboratories.

    Why the other options are wrong

    • AThe aPTT is mainly used to monitor unfractionated heparin therapy, not warfarin.
    • BA platelet count measures the number of platelets, not warfarin's effect on clotting factors.
    • DD-dimer reflects fibrin breakdown after clotting and is not used to adjust warfarin doses.

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