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Laboratory Test Directory

Anti-CD20 Rituximab Monitor


Name Method Department Units
Anti-CD20 Rituximab Monitor Flow cytometry
Core Lab, Flow Cytometry %

Battery Members

CD19/20, CD45, Absolute CD19/20

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume

Purple tube (EDTA)

3 mL 3 mL

Room temperature - 24 hour(s)

Specimen Preparation

  • Mix by gentle inversion immediately after collection
  • Do not centrifuge
  • Keep at room temperature
  • Transport to laboratory as soon as possible

Reasons for Rejection

  • Clotted specimen
  • Wrong collection tube
  • Refrigerated specimen


This test is for patients currently on Rituximab (anti-CD20 drug) or prior to initiation (baseline). A CBC with differential (CD) must be ordered along with this test for reporting of the absolute CD19/20 count. If a CBC with differential is not ordered, the percent of CD19/20+ lymphocytes will be reported but not the absolute count.

Testing is setup Monday-Friday on dayshift but not on national holidays-plan collection accordingly.  Testing must be completed within 24 hours after specimen collection. Test is not setup on Saturday, Sunday or national holidays.  Testing must be received in the laboratory before 2pm on Friday. If you have any questions please contact flow cytometry at 614-722-5482.

CPT Code

  • 88184
  • 88185 (x2)