Test Catalog

Test ID: CD20B    
CD20 on B Cells, Blood

Specimen Type Describes the specimen type validated for testing

Whole Blood EDTA

Ordering Guidance

This is the correct test to order if specifically confirming the absence of B cells due to suspected primary humoral or combined immunodeficiency or evaluating for CD19 deficiency.


If desirous of only quantitatively measuring total CD19 or CD20+ B cells, order TBBS / Quantitative Lymphocyte Subsets: T, B, and Natural Killer (NK) Cells, Blood or CD20B / CD20 on B Cells, Blood, respectively. Do not order the detailed analysis of B cell subsets for this purpose.


This test should not be ordered for a comprehensive evaluation of peripheral B-cell subsets. For evaluation of memory B-cell subsets, transitional B cells, mature and immature B cells, order IABCS / B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood.


This test should not be used for evaluating presence of CD20 on malignant or nonmalignant B cells. The following test should be used instead, CEE20 / CD20 Cell Expression Evaluation, Varies.

Shipping Instructions

Collect and package specimens as close to shipping time as possible. It is recommended that specimens arrive within 24 hours of collection.

Necessary Information

Date of collection is required.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

For serial monitoring, we recommend that specimen collection be performed at the same time of day.


Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.

Additional Information:

1. Secondary aliquot tubes will be rejected.

2. Testing will be canceled if the specimen is not received ambient.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

1 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Secondary aliquot tube Reject

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container
Whole Blood EDTAAmbient4 daysPURPLE OR PINK TOP/EDTA