Specimen Integrity: Recognizing and Responding to Rejection Criteria
Objective. Students will visually assess a set of prepared training specimens, correctly identify integrity problems using a rejection criteria reference, and state the appropriate corrective action for each.
This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.
VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.
Why Specimen Integrity Matters
Every laboratory result begins with the specimen you collect and deliver. If the specimen is compromised, the result may be wrong — and a wrong result can lead to misdiagnosis, incorrect treatment, or patient harm. Phlebotomy technicians are the first line of defense: you must recognize integrity problems before the specimen reaches the analyzer. Learning the rejection criteria for your facility and acting on them correctly is a core patient-safety responsibility.
The Four Major Visual Integrity Problems
Hemolysis
Hemolysis occurs when red blood cells rupture and release hemoglobin into the serum or plasma. The result is a red or pink tint in what should be a straw-colored, clear serum layer. Mild hemolysis produces a faint pink hue; severe hemolysis turns the serum deep red.
Common causes: Difficult or traumatic venipuncture, using too small a needle gauge with high vacuum, vigorous shaking instead of gentle inversion, drawing through a hematoma, temperature extremes during transport, or failing to allow the alcohol to dry before needle insertion.
Why it matters: Hemolysis falsely elevates potassium, LDH, AST, and several other analytes. Many laboratories reject hemolyzed specimens for these tests entirely.
Lipemia
Lipemia is a milky or turbid appearance caused by a high concentration of lipids (mainly triglycerides) in the blood. It is not caused by collection technique — it reflects the patient's physiological state, most often a recent high-fat meal.
Common causes: Patient was not properly fasted before collection, or the patient has a lipid disorder.
Why it matters: Lipemia interferes with photometric (light-based) assays and can falsely alter results for many chemistry panels. Processing options (ultracentrifugation) exist in some labs; others reject and request a fasting recollect.
Icterus
Icterus means the serum or plasma appears yellow-amber or dark orange due to elevated bilirubin. This is a patient condition, not a collection error.
Common causes: Liver disease, hemolytic conditions, or neonatal jaundice.
Why it matters: High bilirubin interferes with certain colorimetric assays. The laboratory may report a bilirubin index and flag affected results rather than reject the specimen, since recollection cannot fix the underlying physiology.
Clots in Anticoagulated Tubes
An EDTA tube (lavender top) or other anticoagulated tube should never contain a visible clot. A clot means the anticoagulant did not mix properly with the blood.
Common causes: Insufficient mixing by inversion immediately after collection, delay before mixing, or under-filling the tube so the blood-to-additive ratio is off.
Why it matters: A clot consumes platelets and clotting factors, making CBC results — especially platelet count and white cell differential — unreliable. These specimens must be rejected and recollected.
Two Additional Rejection Criteria
Insufficient Volume (Short Draw)
Each tube has a minimum fill volume printed on the label or in the facility policy. When a tube is under-filled, the ratio of blood to additive is incorrect. For coagulation tubes (light-blue top, sodium citrate), a short draw dilutes the blood with too much anticoagulant and invalidates PT/INR and aPTT results. Short draws in EDTA tubes cause red-cell shrinkage.
Corrective action: Recollect if the volume is below the acceptable threshold for the ordered test.
Incorrect Tube Type
Drawing a specimen into the wrong tube type — for example, collecting a specimen requiring a red or gold (SST) tube into a lavender (EDTA) tube — introduces an additive that interferes with the test. EDTA chelates calcium and will falsely lower calcium results; it also prevents serum from forming.
Corrective action: Recollect using the correct tube. Never pour a specimen from one tube into another.
The Rejection Decision: Reject, Process with Comment, or Notify
Not every integrity problem results in automatic rejection. Your facility's specimen rejection policy is the authoritative guide. In general:
- Recollect when the problem invalidates the result and a repeat draw is clinically feasible (clots in EDTA, incorrect tube type, severe hemolysis for affected analytes, significant short draw).
- Process with notation/comment when the condition is a patient physiological state that cannot be corrected by recollection (mild icterus, mild lipemia), or when the clinical team has accepted the risk in writing.
- Notify the ordering provider when recollection may not be safe or feasible (difficult access patients, pediatric patients, oncology patients with limited venous access) and a clinical decision is needed.
When in doubt, contact your supervisor or the laboratory before discarding any specimen.
Safety Points for This Lab
- Treat all training specimens as if they were real patient blood. Wear gloves, lab coat, and eye protection before handling any tube.
- Never open a tube unnecessarily. Observe color and turbidity through the closed tube.
- Dispose of all simulated specimens and used gloves in the designated waste container per your lab's protocol.
- If you are unsure whether a real specimen is acceptable, ask your supervisor — never guess with a patient specimen.
Key terms8
Materials: Panel of prepared training tubes (food coloring, gelatin clots, or simulated specimens), specimen assessment form, rejection criteria reference card, facility specimen rejection policy handout, gloves, lab coat, eye protection
Check: Specimen assessment form reviewed by instructor: 9 of 10 specimens correctly identified and assigned an appropriate corrective action to pass; written case-discussion reasoning must reference the rejection policy.
Practice check8
Answer each question, then check it. Nothing is recorded; this is your own practice.
