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Test Code LAB3924 Cell Count with Reflex Differential, Spinal Fluid (CSF)

Testing Algorithm

Differential will automatically be added to orders with nucleated cell counts above 5 cells/cumm

Performing Laboratory

St. Louis Children's Hospital Laboratory - Hematology

Specimen Requirements

Patient Preparation: None

Collection Container/Tube:

Preferred/Acceptable: 7.0 mL screw-capped, sterile, plastic CSF collection vial

 Submission Container/Tube: If specimen is coming from outside facility send sample STAT in original sterile screw-capped plastic collection vial, making sure it is labeled with sequence number of collection on label (or vial)

Collection Volume: minimum 1.0 mL

Special Instructions: Maintain sterility and forward promptly at ambient temperature.

Sample Rejection

Mislabeled or unlabeled specimens

Samples that are >4 hours old

Clotted specimens: cell count will NOT be done on clotted specimens but the differential will still be performed with a disclaimer added.

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 1 hour from receipt in performing lab

Reference Values

Reference Interval: 

Cell Count
   Total Nucleated Cell Count: 0-5 cells/cumm                                    
    RBC: 0 cells/cumm
Differential
    Segmented neutrophils: 0-6%
    Lymphocytes: 40-80%
    Monocytes: 15-45%    

Critical Value: Any Blasts seen

Critical test results will automatically be called back everytime.

Methodology

Cells enumberated by automated method or Hemocytomer

Differential, if performed, is done on smear prepared by cytocentrifugation method

Limitations

  • NA

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: DO NOT SPIN. Give specimen directly to Heme/Coag bench

Processed Volume: minimum 1.0 mL CSF

Analyte Stability:

Specimen Type Temperature Time
CSF (unprocessed)     Ambient 1 hour
  Refrigerated     4 hours
  Frozen  unacceptable       

 

Test Classification and CPT Code

89050 - cell count

89051 - cell count and diff (if applicable)

LOINC

Tube number: 19157-7

Color CSF: 10335-8

Clarity CSF: 10333-3

Xanthochrom CSF: 13532-7

Total Cells CSF: 19075-1

Nucl Cells CSF: 805-2

RBC: 791-4

Last Reviewed

08/2025