Test Catalog

Test ID: CD79    
CD79a Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Phenotyping leukemias and lymphomas

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

CD79a stains the cytoplasm and membrane of B lymphocytes and megakaryocytes. CD79a is a protein expressed on the surface of B lymphocytes at all stages of maturation, from B-lymphocyte precursors through plasma cells. Its function is to transduce the signal of antigen binding to immunoglobulin into the cytoplasm of the B lymphocyte initiating intracellular signaling. Antibodies to CD79a are diagnostically useful to demonstrate B cell lineage of acute lymphoblastic leukemia, malignant lymphomas and chronic lymphoproliferative disorders.

Interpretation Provides information to assist in interpretation of the test results

This test includes only technical performance of the stain (no pathologist interpretation is performed). Mayo Clinic cannot provide an interpretation of tech only stains outside the context of a pathology consultation. If an interpretation is needed, refer to PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case. All material associated with the case is required. Additional specific stains may be requested as part of the pathology consultation, and will be performed as necessary at the discretion of the Mayo pathologist.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut fresh.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Adams H, Liebisch P, Schmid P, et al: Diagnositc utility of B-cell lineage markers CD20, CD791, PAX5, and CD19 in paraffin-embedded tissues From lymphoid neoplasms. Applied Immunohistochemistry and Molecular Morphology 2009;17(2):96-101

2. Hashimoto M, Yamashita Y, Mori N: Immunohistochemical detection of CD79a expression in precursor T cell lymphoblastic lymphoma/leukaemias. Journal of Pathology 2002;197:341-347

3. Kurtin PJ, Hobday KS, Ziesmer S, Caron BL: Demonstration of distinct antigenic profiles of small B-cell lymphomas by paraffin section immunohistochemistry. Am J Clin Pathol 1999;112(3):319-329