Processing

14% of the CPT · blueprint NHA CPT Test Plan, based on a job analysis completed in 2024

Short answer

Fourteen of the 100 scored items. It covers preparing specimens by centrifuging, aliquoting, freezing or refrigeration; maintaining specimen integrity against temperature, light and time requirements; chain of custody for forensic and blood alcohol work; clinical research protocols and packaging; the laboratory information system; recognising and reporting critical values; distributing results; and contacting patients for re-collection.

Why it matters on this exam

Fourteen items, and the domain that decides whether a correctly collected specimen produces a usable result. Core Knowledge statement k9 — "the impact of pre-analytical errors on test results" — is the theme running underneath all of it.

Key concepts

Preparation (5A, k87, k88). Centrifuging procedures, techniques and equipment; aliquoting procedures; freezing and refrigeration for testing or transport.
Specimen integrity (5B, k89). Handling requirements by temperature, light and time. Some analytes are light-sensitive, some are time-critical, some must be chilled — and the handling requirement is a property of the test, not of the tube.
Chain of custody (5C, k91). Required for forensic studies and blood alcohol. This is the formal documented trail of who held the specimen and when; breaking it makes the result legally useless regardless of its accuracy.
Clinical research protocols (5D, k89). Tube processing, obtaining the correct specimen bag, the air waybill, and packaging. Research specimens have their own destination and their own paperwork.
Coordination and systems (5E, 5F, k92). Communicating with non-laboratory personnel for processing and collection; entering and retrieving specimen data in the laboratory information system; internal and external databases.
Critical values (5G, k93). Recognising and reporting critical values for point-of-care and CLIA-waived testing. A critical value is not simply an abnormal result — it is one requiring immediate notification.
Distributing results (5H, k94). Ensuring results reach the ordering provider and the medical record is updated, per basic protocols.
Re-collection (5I). Contacting the patient when the specimen cannot be used.
Laboratory requirements (k90). CLIA regulations, environmental requirements and conditions, machine calibration, and blood volumes.

Common mistakes

Treating a critical value as something to note and pass on at the end of a shift. The defining feature is that it requires immediate reporting.
Assuming chain of custody is paperwork you can complete afterwards. It documents an unbroken sequence; reconstructing it later defeats its purpose.

Worked example

A specimen for a light-sensitive analyte is collected correctly, labelled correctly, and left on the bench under fluorescent light for an hour before centrifugation. Nothing in the collection was wrong, and the result will still be wrong. This is the pre-analytical error the Core Knowledge block points at: the Processing domain exists because the specimen can be destroyed after a flawless draw, and the handling requirement — temperature, light, time — travels with the test, not with the tube colour.

Original practice questions

ProcessingDifficulty 3/5

Which work does the test plan specifically associate with chain of custody requirements?

APoint-of-care glucose and urine pregnancy testing
BForensic studies and blood alcohol collection
CBlood culture collection and metabolic screening
DCoagulation testing and complete blood counts

Show answer and rationale

Correct: B. Task 5C names forensic studies and blood alcohol. Chain of custody documents an unbroken record of who held the specimen and when, without which a legally significant result is unusable.

C — These are clinical collections without the legal handling requirement.
D — Routine haematology and coagulation work carries no chain of custody obligation.
A — Point-of-care testing has quality control requirements but not chain of custody.

ProcessingDifficulty 3/5

A correctly collected and labelled specimen is left under bright light for an hour before processing. What kind of error is this?

AA post-analytical error, because the result was reported to the wrong provider
BNo error at all, because the collection and labelling were performed correctly
CA pre-analytical error, because handling requirements were not observed
DAn analytical error, because the instrument measured the specimen incorrectly

Show answer and rationale

Correct: C. Task 5B requires maintaining specimen integrity against temperature, light and time requirements. Core Knowledge statement k9 names the impact of pre-analytical errors on test results, which is what this domain exists to prevent.

D — The instrument measured the specimen it was given; the specimen itself had degraded.
A — Post-analytical errors concern reporting and distribution, which had not yet happened.
B — A flawless draw does not protect a specimen from being destroyed afterwards.

ProcessingDifficulty 2/5

What distinguishes a critical value from an ordinary abnormal result?

AIt falls outside the reference range published by the laboratory
BIt was produced by point-of-care rather than by laboratory testing
CIt requires the specimen to be re-collected before it can be reported
DIt requires immediate notification rather than routine reporting

Show answer and rationale

Correct: D. Task 5G is to recognise and report critical values for point-of-care and CLIA-waived testing. The defining feature is urgency of notification, not simply that the number is abnormal.

A — Many results fall outside the reference range without being critical values.
B — Critical values arise from both laboratory and point-of-care testing.
C — Re-collection is a separate task at 5I and is not what defines a critical value.

All 3 Processing questions →

Tools for this topic

Tube and additive lookup — Every tube in the CLSI order with its additive, how that additive works, and the tests it serves. A data table rather than prose, drawn from CLSI for the sequence and the WHO phlebotomy guidelines for the additive detail.

4 flashcards for Processing

Practice this topic

Blueprint-mapped questions with full rationales for every choice.

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Primary references

NHA Certified Phlebotomy Technician (CPT) — Test Plan for the CPT Exam — National Healthcareer Association (NHA) · primary · retrieved 2026-09-22, verified 2026-09-22

Last reviewed: 2026-09-22Next review by: 2026-11-06Draft — pending editorial reviewHow we verify facts