Application:
Monoclonal antibody CD19, clone B-C3 can be applied in flow cytometry and in immunohistochemistry using frozen tissue sections. Progenitor B cells mature in bone marrow and subsequently appear as mature CD19+ B cells in blood (4). After contact with foreign antigens and the appropriate T cell help, they may further differentiate to specific antibody-producing plasma cells. Detection of CD19 expressing cells is important in the diagnosis of leukemic precursor B cells (pre-B ALL), mature B cells (B ALL), and plasma cells. Distinction between subtypes of these (acute) leukemias can be performed using CD19 antibodies together with monoclonal antibodies to cytoplasmic or membrane Ig.
A large number of B cell disorders can be effectively characterized by expression of CD19 and one or more additional antigens. One example is hairy cell leukemia (HCL), which shows specific expression of CD11c, CD19, CD20 and CD103. The combination CD103/CD19 is an important tool for diagnosis of HCL. Other valuable antibody combinations for distinction between different leukemias using CD19 antibodies are CD5/CD19 (e.g. Chronic Lymphatic Leukemia); CD10/CD19 (common ALL and pre-B ALL) and CD19/cyCD79a (Acute B cell leukemia) (5).

Specifications:
Clone B-C3 produces IgG1 immunoglobulins directed against human CD19. B-C3 has been clustered as CD19 during the IVth International Workshop on Human Leukocyte Differentiation Antigens (6). The antigen detected by CD19 is a 95 kDa transmembrane glycoprotein.

Performance Characteristics:
Staining with clone B-C3 (CD19) monoclonal antibody and analysis by flow cytometry is illustrated using a normal blood sample. Direct staining was performed using 10 ml of the PE-conjugated monoclonal antibody preparation and 100 ml of blood sample.

Clone B-C3, CD19

Subclass:	IgG1
Source:	mouse
Cellular expression:	Pan B cells
Positive cells:	CD19 PE 18.4 %
Mean fluorescence units:	CD19 PE 104.6

References:
1. Poppema S. and L. Visser L., In: Monoclonal antibodies in the Characterization of Lymphomas and the Diagnosis of Disease; Proc. of the 9th Biotest Symposium, Institute of Education, London, 1987. Sonneborn H.H. and Tills D. Eds.
2. Moldenhauer, G., et al., In Leukocyte Typing II Human B Lymphocytes, 1986, 61-67, E.L. Reinherz, B.F. Haynes, L.M. Nadler, and I.D. Bernstein eds. (Sprin-ger-Verlag, New York)
3. Meeker, T.C., et al., 1984. Hybridoma. 3: 305.
4. Loken, M.R., et al. 1987. Blood 70: 1316.
5. Rothe, G., and Schmitz, G., Leukemia, 1996, 10: 877-895.
6. Leucocyte Typing IV 1990, Knapp, W. et al, eds. Oxford University Press.

For research only. Not for use in humans. For in vitro use only.