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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Flow Cytometry, CD4

Test Code(s): CD4 / HCCD4

CPT Code(s): 86359, 86361

Test Description: Test Component:

Absolute lymphocyte count, percent and absolute numbers of CD3, CD3 CD4  (T helper/inducer cells)

Methodology: Flow Cytometry

Days Performed: Mon-Fri, dayshift- specimens accepted at anytime.

Turnaround Time: Stat: Not available stat.
Routine: 1 - 4 days.

Specimen Requirements

Specimen: Blood

Collection Instructions: An order for a WBC and differential must accompany request.

Outside clients should send WBC and differential results along with specimen. If no results accompany request, a WBC and differential will be added.

Collection Container: Preferred: Lavender top

Collection Volume: Preferred: 4 mL
Pediatrics: 1 mL

Sample Analyzed: Whole Blood

Volume Required: Preferred: 1 mL
Pediatrics: 0.5 mL

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220) within 6 hours of collection. Keep specimen at room temperature. Do NOT centrifuge.

Outreach Specimen Transport: For BLOOD specimens transport unopened tube at room temperature to UWHC Core Laboratory (B4/220) within 6 hours of collection if the WBC and Differential results do not accompany the specimen.

If sending WBC and Differential results with specimen, specimen must be received within 24 hours of collection.

Unacceptable Criteria: Hemolyzed, clotted, frozen or overheated specimens are not acceptable. Samples greater than 24 hours old at time of analysis are not acceptable.

Stability: Ambient: See Additional Information
Refrigerated: Not acceptable
Frozen: Not acceptable


Reference Interval:

Age 18 and up: 


  Absolute number/uL
CD3: 59-85 767-1903
CD3+CD4+: 37-64 494-1464


Please contact UWHC Flow Laboratory at (608) 263-3868 for pediatric reference intervals.

Test Limitations:

Absolute values will not be calculated if WBC and differential request or results are not received.

Additional Information:

This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories. This test meets the standards for clinical testing. This test should not be regarded as investigational or for research use. The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.


Blood Specimens:

Container Volume Stability Transport

Preferred 4mL

Min. 1 mL

Ambient: 8 hours if CBC & Diff is needed

Ambient: 24 hours if CBC & Diff is not needed

Refrigerated: Not acceptable

Frozen: Not acceptable

Transport within 6 hr if cell count is needed


Transport within 22 hr is cell count not needed.

CD4 Count

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