Written to NHA's CPT test plan
- Safety and Compliance 26%
- Patient Preparation 20%
- Routine Blood Collections 28%
- Special Collections 12%
- Processing 14%
Free · 2026 · 14% of the NHA CPT Phlebotomy Processing practice questions
Processing is 14% of the NHA CPT. Answer 10 questions (6 on Processing) and see your score by domain, with every answer explained. Free, no sign-up.
In the emergency department, a phlebotomist collects a legal (forensic) blood alcohol specimen at law enforcement's request. The tube is sealed and the custody form is started. Before the lab courier arrives, the phlebotomist is paged to a STAT draw down the hall. What is the best action?
Tap an answer, or press A to D
Centrifuging and aliquoting, chilled and light-sensitive specimens, rejection criteria, chain of custody, transport, the LIS and critical values.
What the NHA CPT exam tests in Processing
- Preparing specimens for testing or transport: clotting time before centrifuging, centrifuge operation (balancing, stoppers on, timing), aliquoting, serum vs plasma vs whole blood, separation time limits, refrigeration and freezing
- Specimen integrity: specimens that must be chilled, kept at body temperature or protected from light, time limits, hemolysis, lipemia and icterus, specimen rejection criteria and recollection
- Chain of custody for forensic, blood alcohol and drug testing specimens
- Transport and packaging: biohazard bags and containers, pneumatic tube systems, reference laboratories, clinical research protocols (kits, specimen bags, air waybills, triple packaging, dry ice)
- Laboratory requirements and information systems: CLIA rules, environmental conditions and machine calibration, accessioning, entering and retrieving specimen data in the LIS, internal and external databases, coordinating with non-laboratory staff
- Critical values for point-of-care and CLIA-waived testing: recognizing, reporting to the responsible provider, read-back and documentation
- Distributing laboratory results to ordering providers, updating the medical record, contacting patients for recollection
- Core knowledge applied to processing: blood components and how they separate, pre-analytical errors and their effect on test results (hemolysis, hemoconcentration, additive carryover, wrong tube, delays)
High-yield processing facts
- Whole blood tests (CBC, HbA1c): a well-mixed anticoagulated tube that is NEVER centrifuged.
- Plasma tubes (citrate, heparin, EDTA) can be spun right away. Serum tubes must clot COMPLETELY first: SST about 30 min, orange RST about 5 min, per the tube maker. Anticoagulated patients clot slower. Spinning too early leaves fibrin strands that clog analyzers.
- Spun anticoagulated tube, top to bottom: plasma, buffy coat (WBCs + platelets), RBCs. In gel tubes the gel sits between the serum or plasma and the cells.
- Centrifuge: BALANCE with equal-size, equal-volume tubes directly opposite (use a water balance tube if needed). STOPPERS ON (prevents aerosols, evaporation, contamination, pH change). Close and latch the lid; never open it until the rotor stops. Noise or vibration: turn it off and rebalance. Speed (RCF) and time follow the tube maker and lab procedure.
- Separate serum or plasma from cells within 2 HOURS of collection (CLSI) unless stability data allow longer; cells consume glucose and leak potassium. Glucose falls in unseparated blood without fluoride.
- Aliquoting: PPE with a face shield or splash shield; remove stoppers slowly under gauze, twisting away from you (never pop them); new transfer pipette for each specimen; label every aliquot with the same identifiers plus the specimen type (serum or plasma); never pool specimens.
| Handling | Analytes |
|---|---|
| Chill immediately in an ice-water slurry | Ammonia, lactate, ACTH, gastrin, PTH, homocysteine, catecholamines |
| Keep at 37 °C until separated (heel warmer, heat block) | Cold agglutinins, cryoglobulins, cryofibrinogen |
| Protect from light (amber tube or foil) | Bilirubin (especially newborn), vitamin B12, folate, vitamin A, B6, beta-carotene, porphyrins |
| Do NOT chill (room temperature) | Potassium (chilling unseparated blood raises K); most routine chemistry and hematology until processed |
The full Phlebotomy High-Yield Cram Sheet comes with full prep.
Common processing traps
- Serum tubes clot first (SST about 30 min); plasma tubes can be spun immediately; a CBC is never spun.
- Balance the centrifuge, keep stoppers on, don't open it until the rotor stops.
- Separate serum or plasma within 2 h of collection.
- Ammonia and lactate go on ice; cold agglutinins stay warm; bilirubin is protected from light.
- Never chill a potassium specimen.
- Clotted lavender or light blue, underfilled light blue, and unlabeled specimens are rejected, never fixed.
- Chain of custody: every handoff signed and timed, sealed, never left unattended.
- Critical result: call the responsible caregiver now, read-back, document; no voicemail.
Free Phlebotomy processing practice questions
Question 1
A phlebotomist collects a green-top (heparin) tube for a plasma ammonia level on an inpatient. Which handling best protects the specimen until it reaches the laboratory?
- AWrap it in foil to protect it from light during transport
- BPlace it immediately in a slurry of crushed ice and water and deliver it promptly
- CKeep it at room temperature and deliver it within 2 hours
- DHold it in a heat block at 37 °C until it is centrifuged
Show answer and explanation
Answer: B. An ice-water slurry surrounds the tube and chills it evenly, slowing the metabolic production of ammonia.
Why not A: Light protection is required for analytes like bilirubin and vitamin B12, not ammonia.
Why not C: Ammonia rises quickly in blood kept at room temperature as cells metabolize, so it must be chilled right away.
Why not D: Body-temperature handling is for cold agglutinins and cryoglobulins; warming an ammonia specimen would raise the result.
Remember: Ammonia specimens go immediately into an ice-water slurry and are delivered promptly for processing.
Question 2
A phlebotomist calls a patient's nurse to report a critical point-of-care hemoglobin result, as facility policy requires. Which step best confirms that the nurse received the result correctly?
- AState the result slowly twice so the nurse has time to write it down
- BText the result to the nurse's personal phone so there is a written copy
- CEnd the call once the nurse says "got it" and thanks you
- DAsk the nurse to repeat back the patient's identifiers and the result, then confirm that the read-back is correct
Show answer and explanation
Answer: D. In a read-back, the receiver repeats the information and the reporter verifies it, which catches errors in hearing or recording.
Why not A: Repeating it yourself does not show what the nurse actually heard or wrote. Only the receiver's read-back confirms accuracy.
Why not B: Using a personal device for PHI is not an approved channel. A text also does not replace the required verbal read-back.
Why not C: A simple acknowledgment does not verify that the patient and value were understood correctly.
Remember: For critical results, the person receiving the report reads it back and the person giving it confirms that it is correct.
Question 3
The LIS lists a scheduled collection time of 0500 for a routine morning draw. The phlebotomist actually collects the specimen at 0548. What time should be recorded as the collection time?
- AThe time the specimen is received and scanned in the laboratory
- B0500, because that is the scheduled time in the LIS
- CThe time the provider originally placed the order
- D0548, the time the specimen was actually collected
Show answer and explanation
Answer: D. The actual time of collection, along with the collector's ID/initials, must be documented in the LIS and on the label/requisition, since stability limits and timed results depend on it.
Why not A: Receipt time is a separate LIS field. It is not a substitute for the collection time.
Why not B: The scheduled time is not the collection time. Recording it misstates when the specimen was drawn, which can affect stability limits and timed results.
Why not C: The order time shows when the test was requested, not when blood was drawn.
Remember: Record the actual time of collection, not the scheduled or order time.
Question 4
A phlebotomist is asked to take a cerebrospinal fluid (CSF) specimen from a bedside lumbar puncture to the lab. The facility's pneumatic tube policy lists CSF as a specimen that must not be sent through the tube system. What should the phlebotomist do?
- ADouble-bag the specimen, mark the carrier "fragile," and send it through the tube system
- BSend it through the tube system and call the lab to watch for its arrival
- CHold the specimen for the next scheduled courier round within the hour
- DHand-carry the specimen directly to the laboratory right away
Show answer and explanation
Answer: D. Specimens on the facility's do-not-tube list are delivered by hand, promptly, to protect them from loss or damage.
Why not A: Extra bagging does not override the facility's restriction. The policy exists because CSF is irreplaceable if the carrier fails or the specimen is damaged.
Why not B: Calling ahead still violates the policy and still exposes an irreplaceable specimen to loss or damage.
Why not C: Delay can compromise CSF testing, such as cell counts and cultures. Restricted specimens should be delivered promptly by hand.
Remember: Follow the facility's pneumatic tube exclusion list and hand-deliver restricted or irreplaceable specimens such as CSF.
Question 5
When liquid diagnostic specimens are shipped as "Biological Substance, Category B" (UN3373) using triple packaging, where is the absorbent material placed?
- ABetween the primary container and the leakproof secondary container, enough to absorb the entire contents
- BInside the primary tube, mixed with the specimen
- CNowhere, because leakproof primary tubes make absorbent material unnecessary
- DOnly between the secondary container and the rigid outer package
Show answer and explanation
Answer: A. Absorbent between the primary and secondary containers soaks up all the liquid if a primary container leaks or breaks.
Why not B: Absorbent material is never placed in the specimen itself. It would ruin the specimen for testing.
Why not C: Triple packaging for liquids requires absorbent material even when the primary containers are leakproof.
Why not D: Absorbent placed only outside the secondary container would not absorb a primary-container leak, because the liquid would pool inside the secondary container. The absorbent must surround the primary container inside the secondary and be able to absorb the entire contents.
Remember: UN3373 triple packaging means a leakproof primary container, absorbent material inside a leakproof secondary container, and a rigid outer package.
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