Application:
CD138 antibodies, clone B-B4, can be applied in flow cytometry and in immunohistochemistry using frozen and paraffin embedded tissue sections. Immunohistochemical application of antibody B-B4 includes reactivity with B cells in lymphoid follicles, plasma cells, epithelium/endothelium in various organs. CD138 antibodies are used in the detection and monitoring of multiple myeloma, a lympho-proliferative B cell disease, in which malignant plasma cells produce large amounts of immunoglobulins. Rapid and sensitive determination of plasma cell isotype and clonality is carried out by staining for BB4 antigen and cytoplasmic Ig (light and heavy chains) (8).
In addition, since no reactivity is found with CD34-positive precursor cells in bone marrow B-B4 can be used for bone marrow purging prior to autologous transplantation (9).
Another antibody commonly used to detect plasma cells is CD38. However, since CD38 is also expressed on pre-B cells, thymocytes, activated T cells, basophils, natural killer cells, and monocytes it is not a specific plasma cell marker. Antibody B-B4 can be helpful in identifying plasma cells in human bone marrow by two color immunofluorescence analysis with antibodies B-B4 and CD38. All cells recognized by monoclonal antibody B-B4 fall within the CD38-bright population (3). Flow cytometric detection of plasma cells is very sensitive, since as few as 0.5% of plasma cells are detectable in a mononuclear cell population.

NB. Care should be taken when using CD138 since the B-B4 molecule, Syndecan-1, is subject to down modulation as a result of freezing and thawing, from trypsinization or from allowing the blood sample to stand too long. If BB4 is lost due to freezing, thawing or trypsinization its expression on vital cells can be restored by incubation of the cells in RPMI for up to 2 hours at 37 degrees C. In the case of fresh blood, the cells should be labelled within 6 hours of sample taking. After this time the B-B4 disappears quite rapidly. If the cells must be kept longer then the blood may be fixed in 1% paraformaldehyde.

Specifications:
Clone B-B4 produces IgG1 immunoglobulins directed against the human syndecan-1 antigen. B-B4 has been officially assigned to CD138 during the 6th Workshop on Human Leucocyte Antigens,1996 (6). Syndecan-1 is a 30.5 kDa heparan sulphate proteoglycan, probably involved in cellular matrix formation. Reactivity of B-B4 with malignant cells has been shown for 70 - 100 % of multiple myeloma cells and B cell chronic lymphocytic leukemia . Expression of syndecan-1 appears to depend on active protein synthesis and therefore careful preparation of cells for flow cytometric analysis is important.

Performance Characteristics:
B-B4 (CD138) monoclonal antibody, was analysed by flow cytometry according to protocol using a sample of U266 cells (myeloma derived cell line). Direct staining was performed using 10 ml of the PE-conjugated monoclonal antibody preparation and 100 ml cell suspension.

Clone B-B4, CD138

Subclass:	IgG1
Source:	mouse
Cellular expression:	(malignant) plasma cells, endothelial cells, fibroblasts
Positive cells:	CD138 PE 97.8%
Mean fluorescence units:	CD138 PE 1357.9

References:
1. Zhang et al. 1994. Blood, 83, 3654-3663,
2. Borset et al. 1993. Br.J.Hematol, 85, 446-451
3. Pellat et al..1994. Blood, 84, 2597-2603
4. Van Camp, B. et al. 1990. Blood, 76, 3777,
5. Harada, H. et al.. 1993. Blood, 81, 2658
6. Clement, C. et al.. Leucocyte Typing V, Boston, Eds. S.F. Schlossman et al. Oxford Univ. Press, p714-715, (1995).
7. Wijdenes, J., et al. 1996. Brit.J. Haematol. 94.318-323.
8. Van Zaanen, H.C.T. et al. 1995.Brit. J.Haematol., 91, 55-59.
9. Vooijs, W.C., et al. 1996.Cancer Immunol. Immunother. 42. 319-328.
10. Ocqueteau,M et al. 1996. Br. J. Haematol. 95,489-493

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