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7.2 Specimen Quality Assessment & Rejection

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AMCA PTC Phlebotomy Technician Exam

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1 Chapter 1: Introduction & Exam Overview

1.1 Current Exam Facts & Logistics 1.2 Exam Blueprint & Study Strategy

2 Chapter 2: Professionalism & Regulatory Compliance

2.1 Professional Conduct, Diversity & Communication 2.2 Scope of Practice & AMCA Code of Ethics 2.3 Patient Rights, Consent & Documentation Basics 2.4 Patient Privacy & HIPAA Compliance 2.5 CLIA, OSHA Oversight & Incident Reporting 2.6 Continuing Education & Recertification

3 Chapter 3: Infection Control & Safety

3.1 OSHA Bloodborne Pathogens Standard & Exposure Control 3.2 Hand Hygiene & Respiratory Etiquette 3.3 Personal Protective Equipment & Standard Precautions 3.4 Transmission-Based Isolation Precautions 3.5 Cleaning, Disinfection & Sharps Disposal 3.6 Emergency Care, First Aid & CPR Response 3.7 Workplace Safety: CDC, OSHA & NFPA

4 Chapter 4: Patient Identification, Assessment & Site Preparation

4.1 Requisition Review & Professional Introduction 4.2 Two-Identifier Rule & Misidentification Protocol 4.3 Collection Compliance & Patient History Assessment 4.4 Patient Positioning for Safe Collection 4.5 Venipuncture Site Selection & Anatomy 4.6 Aseptic Site Preparation 4.7 Tourniquet Use & CLSI Guidelines

5 Chapter 5: Equipment Selection & Maintenance

5.1 Tube Additives & Color Selection 5.2 Analytical Interference Factors 5.3 Antiseptic Agent Selection 5.4 Venipuncture Equipment Selection 5.5 Capillary & Non-Blood Collection Equipment 5.6 Equipment Quality Control & Inspection

6 Chapter 6: Collection of Blood & Non-Blood Specimens

6.1 Venipuncture Procedure & Needle Technique 6.2 CLSI Order of Draw 6.3 Prioritizing Timed, STAT & Fasting Specimens 6.4 Chain of Custody Collections 6.5 Capillary Puncture Methods 6.6 Collection Complications & Response 6.7 Special Patient Circumstances 6.8 Blood Culture Collection 6.9 Special Collections: GTT, TDM & Blood Bank 6.10 Point-of-Care Testing 6.11 Blood Volume & Tube Fill Requirements 6.12 Non-Blood Specimen Collection 6.13 Post-Puncture Patient Care 6.14 Recording Collection Details 6.15 Measuring & Recording Vital Signs

7 Chapter 7: Specimen Processing & Transportation

7.1 Specimen Labeling & Inversion 7.2 Specimen Quality Assessment & Rejection 7.3 Centrifugation & Aliquoting 7.4 Preparing Non-Blood Specimens for the Lab 7.5 Special Transport, Delivery & Corrective Action

7.2 Specimen Quality Assessment & Rejection

Key Takeaways Explain This Topic AI

Unlabeled or mislabeled blood tubes are subject to immediate, absolute rejection with zero tolerance; specimens can never be relabeled retroactively.

Hemolysis releases intracellular contents, falsely elevating Potassium, LDH, AST, and Iron, while diluting red blood cell counts.

Sodium Citrate (Light Blue) coagulation tubes require a strict 9:1 blood-to-anticoagulant ratio; under-filled tubes (QNS) produce falsely prolonged PT/INR and PTT results.

Visual evaluation post-centrifugation reveals Hemolysis (pink/red), Lipemia (milky white from high triglycerides), and Icterus (dark yellow/brown from high bilirubin).

Point-of-Care Testing (POCT) requires running daily liquid Quality Control (QC) at two concentration levels (High and Low); if QC fails, patient testing is strictly prohibited.

Last updated: July 2026

7.2 Specimen Quality Assessment & Rejection

When a specimen arrives in the clinical laboratory, it undergoes rigorous inspection prior to analysis. If pre-analytical errors compromise sample integrity, the specimen must be formally rejected and recollected. Phlebotomists must understand why specimens are rejected and master Point-of-Care Testing (POCT) quality control procedures.

Specimen Rejection Criteria (Pre-Analytical Errors)

Laboratory specimen rejection is a vital patient safety defense. Analyzing a compromised specimen yields inaccurate diagnostic data that can lead to misdiagnosis, incorrect drug dosing, or inappropriate medical intervention.

Primary Reasons for Specimen Rejection

Unlabeled or Mislabeled Tubes : Absolute zero-tolerance policy. If a tube lacks required identifiers or if label data mismatches the requisition, the tube MUST be rejected. No one is permitted to relabel an unlabeled tube post-collection .

Hemolyzed Specimen : Ruptured erythrocytes release intracellular constituents into plasma/serum, turning it pink or red. Causes false elevation of Potassium ( K + K^+ K + ), LDH, AST, Iron, and Magnesium .

Clotted Specimen in Anticoagulated Tube : Micro-clots or macro-clots in EDTA (Lavender) or Sodium Citrate (Light Blue) tubes indicate inadequate inversion mixing. Clots consume fibrinogen and platelets, invalidating CBC and coagulation results.

Quantity Not Sufficient (QNS) : Inadequate blood volume collected for the required additive ratio.

Light Blue Top (Sodium Citrate) : Demands a strict 9:1 blood-to-anticoagulant ratio (90% blood, 10% liquid citrate). Under-filling results in excess free citrate binding calcium in the test system, causing falsely prolonged Prothrombin Time (PT/INR) and Partial Thromboplastin Time (PTT) .

Incorrect Tube Type / Additive : Drawing a lavender tube instead of a green tube for chemistry panels.

Expired Tube Used : Expired evacuated tubes lose vacuum (causing under-filling) and experience additive degradation.

Contaminated Specimen : Drawing blood above an active intravenous (IV) line dilutes the specimen with IV fluid (dextrose, saline) or contaminates it with heparin. +-------------------------------------------------------------------------+

  • | PRE-ANALYTICAL REJECTION SUMMARY |
  • +-------------------------------------------------------------------------+
  • | Rejection Reason | Root Cause | Impact |
  • +-----------------------+-----------------------------+-------------------+
  • | Mislabeled Tube | Bedside protocol failure | Absolute Rejection|
  • | Hemolysis | Shaking / Small needle | False High K+/LDH |
  • | Clotted EDTA | Under-inversion | Invalid CBC |
  • | QNS Light Blue (<90%) | Early pull / Vacuum loss | False High PT/INR |
  • | IV Contamination | Drawn above IV line | False High Glucose|
  • +-------------------------------------------------------------------------+

Visual Inspection & Interference Indices

Following centrifugation, serum or plasma is visually evaluated against three primary visual interference indices: Hemolysis, Lipemia, and Icterus . +-------------------------------------------------------------------------+

  • | SERUM / PLASMA VISUAL INTERFERENCE |
  • +-------------------------------------------------------------------------+
  • | Normal Serum: Clear, Pale Yellow / Straw Color |
  • | Hemolyzed Serum: Clear to Cloudy, Pink to Deep Red |
  • | Lipemic Serum: Opaque, Milky White / Turbid |
  • | Icteric Serum: Clear, Dark Yellow to Deep Amber / Brown-Green |
  • +-------------------------------------------------------------------------+
  • 1. Hemolysis Index (Pink to Red)

Appearance : Clear to cloudy serum/plasma displaying a pink, bright red, or dark ruby tint.

Cause : Hemoglobin released from ruptured red blood cells. Common collection causes include using too small a needle (e.g., 25-gauge), pulling syringe plungers back forcefully, drawing through a hematoma, vigorous tube shaking, or centrifuging unclotted blood.

Analyte Interference :

Severely Falsely Elevated : Potassium ( K + K^+ K + ), Lactate Dehydrogenase (LDH), Aspartate Aminotransferase (AST), Iron, Magnesium, Phosphorus.

Falsely Decreased : Red Blood Cell (RBC) count, Hematocrit (Hct).

2. Lipemia Index (Milky White)

Appearance : Opaque, turbid, cloudy, or milky-white serum or plasma.

Cause : High concentration of lipids (triglycerides) and chylomicrons. Typically caused by drawing blood shortly after a high-fat meal (post-prandial specimen) or severe hypertriglyceridemia.

Analyte Interference : Cloudiness scatters light in automated spectrophotometric analyzers, interfering with absorbance readings for hemoglobin, total protein, and electrolyte assays.

3. Icterus Index (Dark Amber / Brown)

Appearance : Clear, dark yellow, deep amber, or brownish-green serum or plasma.

Cause : Excessively high concentration of bilirubin resulting from liver disease, hepatitis, biliary obstruction, or hemolytic anemia.

Analyte Interference : High bilirubin alters colorimetric reactions in creatinine, total protein, and cholesterol testing.

  • Interference Index Visual Appearance Underlying Cause Primary Affected Analytes
  • Hemolysis Pink to Deep Red Ruptured RBCs (Trauma/Shaking) Falsely elevates K + K^+ K + , LDH, AST, Iron
  • Lipemia Milky White / Opaque Elevated Triglycerides (Post-prandial) Spectrophotometric light interference
  • Icterus Dark Yellow / Amber Elevated Bilirubin (Liver disease) Colorimetric chemical interference

Point-of-Care Testing (POCT) & Quality Control (QC)

Point-of-Care Testing (POCT) —also called bedside or near-patient testing—refers to diagnostic testing performed directly at the site of patient care rather than in a central laboratory. POCT delivers rapid turnaround times for immediate clinical decision-making.

Common POCT Procedures

Bedside Blood Glucose : Capillary blood via fingerstick used to monitor diabetic glycemic control.

Coagulation Monitoring (PT/INR) : Portable coagulometers measuring prothrombin time for patients taking Warfarin (Coumadin).

Hemoglobin & Hematocrit (H&H) : Microhematocrit cuvettes evaluating anemia or acute blood loss.

Cardiac Troponin (Rapid Troponin I/T) : Bedside immunoassay evaluating suspected acute myocardial infarction.

Urine Dipstick & Pregnancy (hCG) : Rapid enzymatic reagent strips and lateral flow hCG assays.

Fecal Occult Blood Test (FOBT / Guaiac) : Screening for occult gastrointestinal bleeding. +-------------------------------------------------------------------------+

  • | POCT QUALITY CONTROL (QC) PROTOCOL |
  • +-------------------------------------------------------------------------+
  • | [ Start of Testing Shift ] |
  • | +-----------------------------------------------------------------+ |
  • | | Run Liquid QC Controls: Level 1 (Low) & Level 2 (High) | |
  • | +-----------------------------------------------------------------+ |
  • | | |
  • | +----------------+----------------+ |
  • | | | |
  • | [ QC Passes ] [ QC Fails ] |
  • | | | |
  • | Proceed with Patient STOP! Do NOT test |
  • | Testing Patients. Troubleshoot! |
  • +-------------------------------------------------------------------------+
  • Quality Control (QC) & Calibration Rules

To ensure POCT accuracy, clinical personnel must strictly adhere to CLIA-mandated Quality Control (QC) protocols:

Daily Liquid Control Testing : Run manufactured liquid control solutions containing known target values at two distinct levels :

Level 1 (Low Control Solution) : Verifies analyzer accuracy at abnormally low analyte concentrations.

Level 2 (High Control Solution) : Verifies analyzer accuracy at abnormally high analyte concentrations.

Frequency of QC : QC controls must be run at the start of every shift, whenever opening a new lot of test strips/reagents, following instrument maintenance, or after dropping an analyzer.

Out-of-Control Action Rule : If liquid QC values fall outside acceptable target ranges specified by the manufacturer, NO PATIENT SAMPLES MAY BE TESTED . The phlebotomist must document the out-of-control result, re-run controls with a new reagent strip, recalibrate, or remove the analyzer from clinical service until resolved.

Maintenance Logs : Operators must document daily QC results, cleaning schedules, temperature logs for storage units ( 2 ∘ C 2^\circ\text{C} 2 ∘ C to 8 ∘ C 8^\circ\text{C} 8 ∘ C for strip refrigeration), and electronic calibration records.