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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: CBC with Differential

Test Code(s): CBC

CPT Code(s): 85025

Test Description: Test Component:

White blood cell count, red blood cell count, hemoglobin, hematocrit, MCV, MCHC, RDW CV, RDW SD, and platelet. WBC Differential, RBC morphology and platelet evaluation.

Use of manual microscopy for WBC differential is determined by laboratory personnel during testing.

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.

Specimen Requirements

Specimen: Blood

Collection Container: Preferred: K3EDTA-Lavender top
Also Acceptable: K2EDTA-Lavender top, Pink top tube

Collection Volume: Preferred: 4 mL
Pediatrics: 1 mL

Sample Analyzed: Whole Blood

Volume Required: Preferred: 1 mL
Pediatrics: 0.25 mL in microtainer

Specimen Transport: Transport specimen to the laboratory at ambient temperature.

Unacceptable Criteria: Clotted specimens are not acceptable. Tubes with <25% of fill volume.

Stability: Ambient: HCT, MCV, RDW CV, RDW SD, MCHC, Differential - 8 hours. WBC, RBC, Hgb, Platelet, - 24 hr
Refrigerated: Not acceptable
Frozen: Not acceptable


Reference Interval:

For reference interval information,

     see individual tests.

RDW CV reference interval:  
   Age %
   0 days-29 days 11.5-18.0
   30 days-23 months 10.0-16.0
   2-9 years 10.0-15.0
   10-17 years 10.0-14.0
   18 years and up 11.7-14.7
RDW SD reference interval:  
   18 years and up 36.0-46.0 fL
MCV reference interval:  
   Age fL
   0-29 days 102-115
   30 days-5 months 74-115
   6 months-23 months 72-88
   2-9 years 76-90
   10-17 years 78-95
   18 years and up 80-97
MCHC reference interval:  
   0 days and up: 32-36 g/dL

Additional Information:

Differential results may be delayed if a hematopathologist review is warranted. A professional fee may be associated with this test.

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