White Blood Cell Count

Cleveland HeartLab B, Test, W


CPT Code: 85048
Order Code: 1378
ABN Requirement: No
Specimen: EDTA Whole Blood
Volume:  1.0 mL
Minimum Volume:  0.5 mL
Container: EDTA (Lavender Top tube)


  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 8-10 times immediately after draw. DO NOT SHAKE.
  3. Do not centrifuge.

Transport: Store EDTA whole blood at 2°C to 8°C after collection and ship the same day per packaging instructions provided with the Cleveland HeartLab shipping box.


Ambient (15-25°C): Not Acceptable
Refrigerated (2-8°C):
5 days
Frozen (-20°C):
Not Acceptable
Deep Frozen (-70°C):
Not Acceptable

Causes for Rejection: Specimens other than EDTA whole blood; improper labeling; samples not stored properly; samples older than stability limits; clotted samples; grossly hemolyzed samples; samples drawn from above an IV

Methodology: Flow Cytometry

Turn Around Time:  1 to 3 days

Reference Range:

TestAge/GenderReference Range
White Blood Cell Count0-1 month5.0-21.0 K/uL
2-6 months5.0-19.5 K/uL
7 months – 2 years6.0-17.0 K/uL
3-6 years5.0-13.5 K/uL
7-12 years5.0-13.5 K/uL
≥13 years3.7-11.0 K/uL


Critical Values:

TestAgeCritical Value
White Blood Count2-11 years old≥40 K/µL
White Blood Count≥12 years old≥50 K/µL
White Blood CountAll Ages≤2 K/µL

Use: The WBC is used to diagnose and monitor infections or inflammatory processes, as well as screen for a number of diseases, including leukemia and lymphoma. The test can also be used to monitor bone marrow function.

Limitations: Megakaryocytes, giant platelets, clumped platelets or platelet satellitism may falsely elevate the white blood cell count. Hemoglobin S, C and F, or hereditary or acquired spherocytosis may cause an increase in the WBC values. Abnormal proteins as seen in multiple myeloma and Waldenstrom’s macroglobulinemia may falsely increase the WBC count. Fibrin clots may affect the white cell counts.

Additional Information: The WBC may be affected by age and sex, as well as certain medications. In addition, individuals who have undergone splenectomy may have slightly elevated white blood cell counts.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.