CPT: 85048

Expected Turnaround Time

24 Hours

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements


Whole blood


EDTA (Lavender Top Tube)

Storage Instructions

Room Temp., Refrigerated (2-8 C)

Stability Requirements

Room temp. 48hrs., Refrigerated 48 hours

Test Details

Additional Information

Our blood contains a certain white blood cell count (WBC, leukocytes or leukocytes) which, as part of the body’s immune system, helps the body fight infection. A white blood cell (WBC) count measures the amount of white blood cells in a sample of a person’s blood. The number of white blood cells in the body differs between individuals or at different ages in their lives. The normal white blood cell count in a healthy adult is between 4,000 and 11,000 WBCs per microliter (μl or mcL) or cubic millimeter (mm3) of blood, though this may differ between males and females, and healthy children and young people usually have more. 

There are several kinds of white blood cells (WBCs), including neutrophils, eosinophils, lymphocytes, monocytes and basophils. Each variety plays a different role in protecting the body from foreign pathogens such as viruses, bacteria, fungi and parasites. White blood cells also defend the body from allergens, mutated cells, such as cancer, and foreign matter, such as splinters, and remove dead cells, old red blood cells and other debris.

A white blood cell count checks both the overall levels of white blood cells in the blood, as well as the overall proportion of different types of white blood cells. 

The purpose of a WBC count is to determine whether the total number of WBC is within a healthy range. This test is often performed alongside other blood testing, such as a CBC, which also measures other contents of the blood like red blood cells and platelets. 

Knowing the WBC count can help diagnose infections, conditions that cause inflammation, allergic reactions, and cancers of the blood and lymphatic system. A WBC count is also used to monitor the person’s response to certain medical treatments that can affect the immune system including chemotherapy and medications that suppress the immune system. 

A WBC count measures the total number of WBCs contained in a sample of blood. WBC, also called leukocytes, are an important part of the immune system. Made in bone marrow, WBC helps defend the body against infections and disease. There are five types of WBC, each supporting the immune system in a different way. 

The WBC count is usually expressed as thousands of cells per microliter (cells/μL). Around 100 billion WBC are produced each day in bone marrow. As they mature, WBC can be found in blood and the lymphatic system.  

There are five types of WBC: 

  • Basophils 
  • Eosinophils 
  • Lymphocytes 
  • Monocytes 
  • Neutrophils 

A WBC count measures the total amount of all kinds of WBC. If a doctor needs information about the number of individual types of WBC, this information is provided in the WBC differential test. 


  1. Marcogliese AN, Hensch L. Resources for the hematologist: interpretive comments and selected reference values for neonatal, pediatric, and adult populations. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 159. 
  2. Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31. 

Statement on Medical Necessity
All ordered tests should be medically necessary for the diagnosis or detection of disease, illness, impairment, symptom, syndrome, or disorder and the results should be used in the medical management and treatment decisions for the patient. Solaris requires ICD-10 codes with each order for lab testing and both the tests ordered and the diagnosis should be documented in the provider’s medical record for the patient. The United States Department of Health and Human Services, Office of Inspector General, takes the position that a provider who orders medically unnecessary tests may be subject to civil penalties.

Panels and Profiles
Solaris offers Providers the convenience of ordering test combinations in a group at times with the flexibility to choose appropriate test(s) for individual patients. Providers should only order those tests that he or she believes are medically necessary for each patient, and a lesser inclusive profile or individual tests should be ordered if not all tests in the test combination/profile are medically necessary. All tests offered in a test combination/profile may be ordered separately as individual tests. Solaris encourages clients to contact their Solaris representative if the testing configurations shown do not meet individual needs for any reason, or if some other combination of procedures is needed.

CPT Codes
CPT Codes listed are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are the responsibility of the billing party and are listed here for informational purposes. Correct coding may vary from one carrier to another. Solaris may bill specific carriers using codes other than what is shown.


For questions or inquiries related to testing please reach out to
customerservice@solarisdx.com or contact us by phone at (844) 550-0308.