Preventing Test Not Performed (TNP) Results & Specimen Rejections

Preventing Hemolysis in Blood Samples

Reduce Testing Not Performed (TNP) Results Due to Hemolysis

Hemolysis occurs when red blood cells break apart during specimen collection, handling, transport, or processing. Hemolyzed specimens can interfere with testing, impact result accuracy, and may lead to Testing Not Performed (TNP) outcomes, specimen rejection, or recollection.

Why Hemolysis Matters

Hemolysis can:

• Affect the accuracy of test results
• Cause specimens to be unsuitable for testing
• Lead to TNP results or specimen rejection
• Delay patient diagnosis and treatment
• Increase costs associated with recollection and retesting

Common Causes of Hemolysis

Most hemolysis events can be prevented and are often caused by:

• Improper collection technique
• Using an inappropriately small needle
• Underfilling collection tubes
• Vigorous shaking of specimen tubes
• Forcing blood from a syringe into a collection tube
• Exposure to improper temperatures
• Delayed specimen processing or shipment

Best Practices for Specimen Collection and Handling

Help maintain specimen integrity by following these guidelines:

• Use the recommended collection device and needle size whenever possible.
• Fill collection tubes to the appropriate volume.
• Mix tubes gently according to manufacturer instructions.
• When transferring from a syringe, remove the needle and allow blood to flow gently into the tube.
• Transport specimens promptly and within test-specific temperature requirements.
• Follow recommended centrifugation and processing procedures.

Tests Commonly Impacted by Hemolysis

Even mild hemolysis may affect testing for select assays, including:

• Fungitell^®
• ImmuKnow^®
• Chronic Urticaria
• Plasma Histamine
• MBL Pathway Function
• Pneumococcal/Pneumo Avidity
• Anti-IgA
• C1 Functional
• C1 Inactivator/Complement
• C1q/Low Level IgA
• Tetanus, Diphtheria, Hib, and MBL Oligomer
• PCR Assays

At a Glance: The Most Common Causes of TNP

Hemolysis Reference Guide

Use the reference chart below to help identify varying levels of hemolysis. Specimens with moderate to severe hemolysis may not meet testing requirements for certain assays.

	Minimal	Sample quality acceptable for testing
	~20 mg/dL
	~50 mg/dL
	~100 mg/dL	Sample quality does not allow for testing
	~250 mg/dL
	~500 mg/dL
	~1000 mg/dL

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General Requirements and Guidelines

We make every possible effort to maintain the integrity of the patient’s specimen to ensure accurate test results. To assist with this effort, we encourage your review of, and adherence to, the following general requirements when collecting and submitting specimens:

• Collect specimen in the correct container specified on the test page; broken or leaking specimen containers will not be accepted for testing.
• All specimen containers must be received with at least TWO unique patient-specific identifiers in order to qualify for testing.
  • Examples of acceptable identifiers include but are not limited to: patient name, date of birth, hospital number, social security number, requisition number, accession number and unique random number.
• Ensure each specimen container has the date of collection. For cell function testing, also include the time of collection.
• Package specimen in an individual resealable bag. Multiple specimens should NEVER be placed together in a single resealable bag.
• Ship specimen in compliance with all applicable shipping regulations such as IATA and DOT.
• Maintain specimen at the temperature specified on the Specimen Information section of the Test Menu.
• Ensure the specimen is shipped priority overnight for arrival at Eurofins Viracor within the specified required timeframe as stated in the Specimen Information section of the test menu page.
• The specimen must be sent with a manifest, requisition or test request form which matches the patient identifiers, source, and test name.
• Tissue specimens from the brain will not be accepted if CJD is suspected. Processing of any brain or brain stem tissue specimen will be held until the lab receives confirmation that Creutzfeldt-Jakob Disease (CJD) is not a suspected diagnosis.

Eurofins Viracor handles specimen types that must be separated by temperature requirements. If the above-mentioned conditions and test-specific specimen requirements are not met, Eurofins Viracor will notify the client regarding the reason and recommended resolution. This notification will occur either verbally through a phone call or through receipt of a lab report detailing the problem. If you have concerns or questions about submitting a specimen, please contact Client Services at 1-800-305-5198.