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Test Code BCD20 B Cell CD20 Quantification

Collection Container

Green top sodium heparin or lithium heparin (perferred), Lavender EDTA (acceptable)

Specimen Required

Place specimens in a bag near the flow cytometry rack at LCRI.  The tubes should remain lying down.  Do not place upright in the rack.  

Specimen Volume

3 mL green top sodium heparin or lithium heparin preferred, Lavender top acceptable.

Minimum Specimen Volume

1 mL green top sodium heparin or lithium preferred, Lavender top acceptable.

Special Handling Instructions

An additional lavender top (EDTA) tube must be collected at the same time (within 6 hours maximum) as the IMDEF so that a complete blood count with differential (CBCD) may be ordered (See complete blood count with differential).  If a CBC is ordered on the requisition please order CBDIF.


Transport Temperature

Room Temperature

Specimen Stability

Transport specimen to the Flow Cytometry laboratory as soon as possible.

Reasons for Rejection

Specimen refrigerated or exposed to extreme heat; specimen clotted or hemolyzed; specimen more than 48 hours old when received in the laboratory.


Numeration of specific subpopulations with monoclonal antibodies to lymphocyte antigens by flow cytometry.

Day(s) and Time(s) Performed

Draw anytime.  Test performed day shift Monday-Saturday; not on Sunday or holidays (Holidays include the weekdays celebrated by Baystate Medical Center when an actual holiday falls on a weekend).  The specimen is acceptable as long as it is received by the flow cytometry laboratory within 48 hours of collection.

Additional Information

Assessing the number of B-cells expressing the target molecule (CD20) of interest in the context of initiating and monitoring therapeutic monoclonal anti-CD20 antibody therapy (rituximab, ofatumumab, tositumomab, etc.) for hematologic malignancies or for immune modulation.

Units of Measure

(%) and (k/mm3)

Turnaround Time

1-2 Days

CPT Code


88185 x 2

Reference Ranges

Reference Range for adults:                             

CD20+ (B-cell) cells:  4-24%; 27-423k/mm3

CD19+ (B-cell) cells:  5-25%; 26-429k/mm3