Specimen processing begins immediately after blood collection and includes labeling, handling, transportation, processing, and storage. Proper processing preserves specimen integrity so laboratory results accurately reflect a patient’s condition. Errors during this stage can lead to specimen rejection, delayed diagnosis, repeat collections, or inaccurate test results that affect patient care.

Because most laboratory errors occur during the pre-analytical phase, phlebotomists must understand specimen processing as well as blood collection. Certification exams, including the NHA CPT, ASCP PBT, and AMT RPT exams frequently assess specimen handling, transport, storage, and pre-analytical errors.

This guide explains the specimen processing workflow, common errors, and best practices that support patient safety, laboratory quality, and exam success. After studying, reinforce your knowledge with our Specimen Processing Quiz to identify weak areas and prepare more effectively for your certification exam.

What Is Specimen Processing?

Specimen processing is the series of procedures performed after specimen collection to prepare it for laboratory testing. Depending on the test, processing may include verifying patient information, inspecting the specimen, transporting it under proper conditions, centrifugation, separating serum or plasma, storing the specimen correctly, and routing it to the appropriate laboratory department.

The goal is to maintain specimen integrity so test results accurately reflect the patient’s condition. Improper handling can alter specimens, resulting in inaccurate results, rejection, delayed testing, or repeat collection.

Phlebotomists are responsible for key pre-analytical tasks, including:

• Correct patient identification
• Selecting the correct collection tube and following the order of draw
• Labeling specimens immediately after collection
• Properly mixing additive tubes
• Protecting specimens during transport
• Following laboratory and facility procedures

Laboratory personnel typically verify specimens, perform centrifugation, aliquoting, storage, and testing.

Because most testing errors occur before analysis, standardized specimen processing improves accuracy, reduces preventable errors, and supports patient safety.

Exam Tip: Know which responsibilities belong to the phlebotomist (collection, labeling, transport) and which belong to laboratory personnel (verification, centrifugation, aliquoting, testing, storage).

Specimen Processing Workflow

Specimen processing follows a standardized sequence that protects specimen quality from collection through testing.

1. Verify the Test Order and Patient Identity

Confirm the test request and verify the patient’s identity using at least two approved identifiers according to facility policy. For a complete overview of patient identification, consent, and pre-collection preparation, see our Patient Preparation Study Guide.

2. Collect the Specimen

Use the correct collection tube, follow the proper collection procedure and order of draw, and collect the required blood volume to maintain the correct blood-to-additive ratio.

3. Label the Specimen

Label each specimen immediately after collection in the patient’s presence using the required identifiers. Incorrect or delayed labeling is a leading cause of specimen rejection.

4. Mix Additive Tubes

Gently invert additive tubes the recommended number of times. Do not shake tubes, as vigorous mixing may cause hemolysis.

5. Transport the Specimen

Deliver specimens promptly while maintaining required handling conditions, such as room temperature, refrigeration, protection from light, transport on ice, or body temperature when specified.

6. Inspect the Specimen

Laboratory personnel verify patient identification and inspect the specimen for acceptable volume, labeling, tube selection, hemolysis, clotting, leakage, and other quality issues. Unacceptable specimens may require recollection.

7. Process the Specimen

Depending on the ordered test, specimens may be allowed to clot, centrifuged, separated into serum or plasma, aliquoted, or routed to specialized laboratory sections.

8. Store or Test the Specimen

Specimens are tested immediately or stored under appropriate conditions until analysis to preserve stability and ensure accurate results.

Exam Tip: Learn both the order of specimen processing and the purpose of each step. Certification exams commonly use scenario-based questions.

Proper Specimen Labeling

Accurate specimen labeling is essential for patient safety and reliable laboratory results. Even a correctly collected specimen may be rejected if it is mislabeled or unlabeled.

Why Labeling Matters

Proper labeling ensures every specimen is matched to the correct patient, reduces identification errors, supports accurate reporting, and meets laboratory quality standards. Accurate patient identification is a critical patient safety practice. The Joint Commission’s National Patient Safety Goals recommend using at least two patient identifiers to reduce identification errors. To learn more about patient identification, infection prevention, and other essential safety practices, see our Safety and Compliance Study Guide.

When to Label

Label specimens immediately after collection and before leaving the patient’s side. Labeling before collection or away from the patient increases the risk of specimen mix-ups.

Required Label Information

Most specimen labels include:

• Patient’s full name
• Second patient identifier (date of birth or medical record number)
• Collection date and time
• Collector’s initials or identification, if required
• Additional information for specialized testing when needed

Many laboratories use barcode labels through the Laboratory Information System (LIS) to improve identification accuracy.

Common Labeling Errors

Common causes of specimen rejection include:

• Missing patient identifiers
• Incorrect patient information
• Illegible handwriting
• Mismatched requisition information
• Label applied to the wrong tube
• Failure to label immediately after collection

Best Practices

• Verify patient identity before collection.
• Label specimens immediately in the patient’s presence.
• Compare the label with the test order.
• Apply barcode labels correctly.
• Follow facility procedures for documentation and corrections.

Exam Tip: Specimens with missing or incorrect patient identifiers are generally unacceptable and usually require recollection. Reinforce these high-yield safety concepts with our Safety and Compliance Quiz before your certification exam.

Specimen Transport

Proper transport preserves specimen integrity between collection and laboratory testing. Delays, temperature extremes, rough handling, or improper packaging can compromise specimen quality.

Transport Promptly

Deliver specimens to the laboratory as soon as possible. Delays can alter analyte concentrations or blood cell morphology and affect test accuracy.

Follow Temperature Requirements

Transport specimens according to laboratory instructions.

Common conditions include:

• Room temperature: Most routine specimens
• Refrigerated: Preserves certain analytes
• Chilled/on ice: Required for specific tests
• Warm: Some specimens must remain near body temperature

Always follow laboratory policies for test-specific handling.

Protect the Specimen

Transport specimens in approved leak-resistant biohazard containers. Keep tubes upright when practical and avoid excessive shaking or rough handling to reduce leakage, breakage, and hemolysis.

Special Handling

Some specimens require:

• Protection from light
• Strict temperature control
• Immediate delivery for time-sensitive testing

Many of these requirements apply to specialized specimens, such as blood cultures and temperature-sensitive tests. For detailed collection and handling procedures, see our Special Collections Study Guide. Failure to follow these requirements may produce inaccurate results or specimen rejection.

Common Transport Methods

Healthcare facilities commonly use:

• Hand delivery
• Courier services
• Pneumatic tube systems (when appropriate)

Best Practices

• Verify specimen labeling before transport.
• Use approved transport containers.
• Follow required time and temperature conditions.
• Handle specimens carefully.
• Deliver promptly and document transport when required.

Exam Tip: Focus on recognizing when specimens require special handling, such as refrigeration, transport on ice, light protection, or immediate delivery.

Specimen Handling Requirements

Proper specimen handling begins immediately after collection and continues until testing is complete. Every specimen must be handled correctly to preserve its integrity and ensure accurate laboratory results. Even a properly collected specimen can become unsuitable if mishandled during the pre-analytical phase.

Maintain Specimen Integrity

Specimen integrity means the sample remains suitable for accurate testing. Following laboratory requirements for collection, transport, processing, storage, and timing helps prevent changes that could compromise test results.

Prevent Hemolysis

Hemolysis occurs when red blood cells rupture and release their contents into serum or plasma, interfering with many laboratory tests.

Common causes include:

• Using a needle that is too small
• Pulling a syringe plunger too quickly
• Forcing blood through a needle into a tube
• Shaking tubes instead of gentle inversion
• Allowing alcohol to remain wet before collection
• Rough handling during transport

Using proper collection techniques and careful handling helps minimize hemolysis. For detailed guidance on venipuncture techniques, tube selection, and the order of draw, see our Routine Blood Collection Study Guide.

Prevent Clot Formation

Anticoagulant tubes must be gently inverted immediately after collection to mix blood with the additive. Inadequate mixing may cause clot formation, making specimens unsuitable for tests such as complete blood counts or coagulation studies.

Avoid Specimen Contamination

Prevent contamination by:

• Following the correct order of draw
• Using sterile technique when required (such as blood cultures)
• Keeping collection equipment clean
• Avoiding transfers between tubes unless laboratory procedures require them

Follow Special Handling Instructions

Some specimens require special handling to maintain stability, including:

• Protection from light
• Refrigeration or transport on ice
• Controlled temperature
• Processing within a specified timeframe

Always follow the laboratory’s specimen collection manual or facility policy.

Handle Specimens Safely

Treat every specimen as potentially infectious by following Standard Precautions. Wear appropriate PPE, use leak-resistant biohazard containers, and handle specimens safely to protect both personnel and specimen quality.

Best Practices

• Verify patient identity before collection.
• Label specimens immediately.
• Gently invert additive tubes as recommended.
• Handle specimens carefully to prevent hemolysis and breakage.
• Follow laboratory requirements for transport, temperature, and processing.
• Report compromised specimens according to facility policy.

Exam Tip: Be able to recognize handling errors such as hemolysis, clotting, contamination, or improper transport, and know how to prevent them.

Centrifugation and Specimen Separation

Many blood specimens require centrifugation before analysis. This process separates blood components by density, allowing serum or plasma to be tested while reducing cellular changes that may affect results.

Why Centrifugation Matters

Whole blood contains plasma or serum, red blood cells, white blood cells, and platelets. Most laboratory tests use serum or plasma rather than whole blood. Prompt separation prevents ongoing cellular metabolism from altering analyte concentrations.

Serum vs. Plasma

Serum	Plasma
Collected in tubes without anticoagulant	Collected in tubes with anticoagulant
Blood must clot before centrifugation	Centrifuged immediately after collection
Does not contain fibrinogen	Contains fibrinogen and clotting factors

The required specimen depends on the laboratory test. For a better understanding of blood components, including plasma, serum, and blood cells, explore our Anatomy & Physiology Study Guide.

Allow Serum to Clot

Serum specimens must clot completely before centrifugation. Processing too early can leave fibrin strands that interfere with testing. Follow manufacturer and laboratory recommendations for clotting time.

Separate Promptly

After centrifugation, separate serum or plasma from blood cells within the required timeframe to preserve analyte stability. When needed, serum or plasma is transferred into a secondary tube (aliquot) for testing or transport.

Separator Gel Tubes

Some collection tubes contain separator gel that forms a barrier between blood cells and serum or plasma after centrifugation, helping maintain specimen stability. However, these tubes are not appropriate for every test, so always use the tube specified by the laboratory.

Common Centrifugation Errors

Common errors include:

• Centrifuging serum before clotting is complete
• Using incorrect centrifuge settings
• Delaying specimen separation
• Ignoring special handling requirements
• Using the wrong collection tube

Following laboratory procedures helps ensure accurate results.

Exam Tip: Know the differences between serum and plasma, when blood should clot before centrifugation, and why prompt separation is important.

Specimen Storage

Proper storage preserves specimen stability until testing. Storage requirements vary by specimen type, test, and laboratory procedures.

Why Storage Matters

Incorrect storage conditions can alter analytes, reduce cell viability, or affect test accuracy. Following laboratory guidelines helps ensure reliable results.

Common Storage Conditions

Depending on the test, specimens may be stored at:

• Room temperature for many routine tests
• Refrigerated to preserve certain analytes
• Frozen for long-term storage or delayed testing
• Protected from light for light-sensitive specimens

Always follow laboratory instructions rather than relying on memory.

Maintain Specimen Stability

To preserve specimen quality:

• Store specimens promptly after processing.
• Keep containers securely closed.
• Avoid repeated freeze-thaw cycles unless permitted.
• Separate serum or plasma from blood cells before extended storage when required.

Specimen Retention

Laboratories retain specimens for a defined period to allow additional testing, result verification, or repeat analysis. Retention time depends on laboratory policy, regulations, specimen type, and testing requirements.

Best Practices

• Follow required storage temperatures.
• Protect specimens from heat, freezing, or light when applicable.
• Store processed specimens promptly if testing is delayed.
• Follow laboratory policies for retention and disposal.
• Document storage and handling when required.

Exam Tip: Certification exams focus less on memorizing individual storage temperatures and more on recognizing that each specimen has specific handling, timing, and storage requirements that must be followed to maintain specimen integrity.

Common Pre-Analytical Errors

The pre-analytical phase includes all steps before laboratory analysis, from test ordering and patient identification to specimen collection, labeling, transport, processing, and storage. Because most laboratory errors occur during this stage, phlebotomists must follow standardized procedures to preserve specimen quality and ensure accurate results.

Patient Identification Errors

Incorrect patient identification is one of the most serious laboratory errors and may result in testing the wrong patient.

Common causes include:

• Failing to verify patient identity
• Using incorrect or incomplete identifiers
• Collecting from the wrong patient
• Mislabeling the specimen

These errors often require recollection and may delay diagnosis or treatment. Reinforce this high-yield topic with our Patient Preparation Quiz.

Incorrect Tube Selection

Using the wrong collection tube or additive can compromise testing.

Examples include:

• Wrong tube color
• Incorrect additive
• Tube not approved for the ordered test

Always verify the required collection tube before collection.

Failure to Follow the Order of Draw

Drawing tubes in the wrong sequence can cause additive carryover, affecting specimen quality and laboratory results. Practice these commonly tested collection topics with our Routine Blood Collection Quiz.

Hemolysis

Hemolysis occurs when red blood cells rupture, releasing intracellular contents into serum or plasma. Common causes include poor collection technique, traumatic venipuncture, vigorous tube shaking, and rough specimen handling.

Clotted Anticoagulated Specimens

Failure to gently invert anticoagulant tubes may allow clot formation, making specimens unsuitable for tests requiring whole blood or plasma.

Insufficient Specimen Volume (QNS)

Collecting too little blood can result in Quantity Not Sufficient (QNS) or an incorrect blood-to-additive ratio, leading to inaccurate results or specimen rejection.

Delayed Processing or Improper Handling

Delays, incorrect storage temperatures, or improper handling can reduce specimen stability and compromise laboratory results.

Preventing Pre-Analytical Errors

Reduce errors by:

• Verifying patient identity
• Using the correct tube and order of draw
• Labeling specimens immediately
• Mixing additive tubes correctly
• Following transport, processing, and storage requirements
• Reporting specimen problems according to facility policy

Exam Tip: Scenario-based questions often ask you to identify the pre-analytical error, explain how it affects specimen quality, and choose the appropriate corrective action.

Specimen Rejection Criteria

Laboratories inspect every specimen before testing. Samples that fail acceptance criteria may be rejected because they cannot produce reliable results.

Common reasons for rejection include:

• Missing, incorrect, or incomplete patient identification
• Wrong collection tube
• Excessive hemolysis
• Clotted anticoagulated specimens
• Quantity Not Sufficient (QNS)
• Leaking or damaged containers
• Improper transport or storage

Reducing Specimen Rejection

Phlebotomists can reduce rejection rates by:

• Verifying patient identity
• Selecting the correct collection tube
• Labeling specimens immediately
• Mixing additive tubes properly
• Following transport, processing, and storage requirements
• Inspecting specimens before transport

Consistent technique reduces repeat collections and improves patient safety.

Exam Tip: Certification exams consistently prioritize patient identification and specimen integrity. Mislabeled, unlabeled, or improperly collected specimens generally require recollection according to laboratory policy.

Quality Assurance and Safety

Quality assurance (QA) uses standardized procedures, training, documentation, and continuous improvement to reduce errors and ensure reliable laboratory testing.

Quality Assurance Best Practices

• Follow laboratory policies and SOPs.
• Verify patient identity.
• Use the correct collection equipment and tube.
• Label specimens immediately.
• Follow handling, transport, and storage requirements.
• Document collection details when required.
• Report collection or specimen problems promptly.

Safety During Specimen Processing

Treat all blood specimens as potentially infectious by following Standard Precautions. Wear appropriate PPE, transport specimens in approved biohazard containers, and dispose of contaminated materials according to facility policy. Damaged or leaking specimens should be managed using established exposure-control procedures.

Documentation and Traceability

Accurate documentation supports specimen traceability, quality improvement, regulatory compliance, and investigation of specimen-related issues.

Exam Tip: Following standardized procedures consistently is one of the most effective ways to prevent pre-analytical errors and ensure patient safety.

Certification Exam Tips

Specimen processing is a major topic on phlebotomy certification exams because it directly affects laboratory accuracy and patient care. Focus on understanding why each procedure is performed rather than memorizing isolated facts.

High-Yield Topics

Review these frequently tested concepts:

• Specimen processing workflow
• Patient identification and specimen labeling
• Collection tube selection and order of draw
• Specimen transport and handling
• Serum vs. plasma
• Clotting before centrifugation
• Causes of hemolysis, clotting, and contamination
• Specimen rejection criteria
• Standard Precautions and laboratory policies

Questions involving blood cultures, temperature-sensitive specimens, and other specialized collections are common on certification exams. Practice these scenarios with our Special Collections Quiz.

Study Tips

• Learn the complete workflow instead of isolated steps.
• Understand how each procedure preserves specimen integrity.
• Practice case-based questions.
• Review key terms such as hemolysis, serum, plasma, aliquot, and QNS.
• Reinforce learning with practice exams and explanation-based review.

Understanding the purpose behind specimen processing helps you answer certification questions confidently and apply these principles in clinical practice. A solid understanding of blood composition and basic human physiology also supports success on certification exams. Test your knowledge with our Anatomy & Physiology Quiz.

Key Takeaways

• Specimen processing begins immediately after collection and continues until testing or storage.
• Proper identification, labeling, handling, transport, processing, and storage preserve specimen integrity.
• Most laboratory errors occur during the pre-analytical phase and are preventable through standardized procedures.
• Timely centrifugation, specimen separation, and proper storage support accurate laboratory results.
• Common reasons for specimen rejection include labeling errors, hemolysis, clotting, incorrect tubes, QNS, and improper transport or storage.
• Quality assurance practices and Standard Precautions improve patient safety, laboratory quality, and regulatory compliance.
• Mastering specimen processing concepts is essential for success on the NHA CPT, ASCP PBT, and AMT RPT certification exams.