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Complete Blood Count with Differential (LAB000634)
Test Mnemonic:

CBC with Diff

Specimen Requirements:

 Routine venipuncture; Collect in EDTA (lavender tube). Micro-collection is acceptable.  The specimen should be collected to the appropriate fill volume stated on the collection tube.  The minimum volume required is 90% of the stated tube volume.


EDTA (lavender tube). Micro-collection tube is acceptable.

Minimum Volume:

 90% of the stated tube volume.  Micro-collections  minimum 250ul, maximum 500uL.


Room Temperature 4 hours.  If testing cannot be completed within 4 hours sample must be refrigerated at 2-8° C.

Specimen Preparation:

ECMO specimens should be delivered directly to the Hematopathology lab.


Stable Refrigerated 2-8° C at for 24 hours.

Causes for Rejection:

Clotted, QNS, identification error, hemolysis.

Reference Range:

By report (reports may vary based on instrumentation, patient age and sex).

Turnaround Time:

 STAT: 1 hour; Routine: 4 hours


 Automated, multi-parameter counting of red blood cells (RBC) and platelets using electronic resistance detection enhanced by hydrodynamic focusing. The hematocrit is measured utilizing cumulative pulse height detection. Hemoglobin is measured using a sodium lauryl sulfate method. WBC count, differential and nucleated red blood cells are evaluated using flow cytometry.


Samples are accepted 24 hours per day.


Galveston Lab, ADC Lab, LCC Lab, CLC Lab


CBC with differential

CPT 4 Code:

 85025. If reflexed additional CPT codes may apply; refer to reflexed test code for applicable codes. Additional charges apply.


Critical Values:

WBC< 2.0 x 103/uL

Hemoglobin <7.0 g/dL (age <2 yrs. old),  <5.0 g/dL  (age ≥2 yrs. old)

Hematocrit : <21% (age <2 yrs. old),  <15.0% (age  2 yrs. old)

Platelets  <50 or > 1000 x 103/uL

Interfering Substances: Clots or fibrin strands; inappropriate anticoagulant; extremely elevated WBC counts; nucleated red blood cells; sickle cells; clumped platelets; giant platelets, circulating micro-megakaryocytes; hemolysis; electrolyte imbalances; warm or cold agglutinins; elevated plasma lipids; elevated chylomicrons; elevated bilirubin; elevated serum urea nitrogen.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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