CD34 (Mucosialin)

CD34 (cluster of differentiation 34), also known as gp105-120 or mucosialin, is a transmembrane protein that is commonly expressed on hematopoietic progenitor cells, as well as on some populations of mesenchymal stem cells and vascular endothelium. It is known to facilitate cell-cell adhesion, and is necessary for the entry of T cells into lymph nodes a critical event that is essential for adaptive immunity to function properly. While much is still to be determined about its exact functionality, the phosphorylation of CD34's intracellular domain by activated protein kinase C, suggests a possible role in signal transduction.

CD34 Structure

---

CD34 is a 105-120 kDa, type I monomeric glycosphoprotein and member of the sialomucin protein family. It consists of a highly conserved cytoplasmic domain and transmembrane domain that is characterized by a well conserved C-terminal region and a heavily glycosylated N-terminal region. The N-terminal region is important for determining CD34 interactions with a variety of different ligands including E- and L-selectins.

CD34 Antibodies

---

Monoclonal CD34 antibodies, designed to recognize human CD34 surface molecules, are frequently used as a biomarker for pluripotent hematopoietic stem cells, and for the identification and purification of progenitor cells. Cells also known to express CD34 surface markers include some populations of mesenchymal stem cell, mast cells and dendritic cells. In clinical research studies, CD34 antibodies have been used to identify angiosarcoma and Kaposi sarcoma, acute myeloid leukemia, soft tissue tumors and to quantify HSCs for cell transplantation. Diseases commonly characterized by CD34 dysfunction include neurofibroma, a type of nerve tumor, and dermatofibrosarcoma, a type of soft tissue sarcoma.

AAT Bioquest offers a comprehensive catalog of CD34 antibodies purified by affinity chromatography and conjugated to a variety of fluorophores under optimal conditions that minimize unconjugated fluorophore and antibody. Available fluorophores include:

• iFluor® dyes - bright, photostable dyes with optimized flow cytometry (FACS), fluorescence imaging and in vivo imaging applications.
• mFluor™ dyes - bright, photostable dyes with optimized for flow cytometry (FACS) applications.
• Alexa Fluor^® dyes - suitable for flow cytometry (FACS) and fluorescence imaging applications.
• Classic dyes - suitable for flow cytometry (FACS) and fluorescence imaging applications.
• Phycobiliproteins and Tandem dyes - intensely bright dyes for flow cytometry (FACS) and multiparametric analysis.

1. FC = Flow Cytometry; ELISA = Enzyme-linked immunosorbent assay; IF = Immunofluorescence; IHC-F = Immunohistochemistry (Frozen); WB = Western Blot.

iFluor® Dyes Labeled to CD34 Antibodies

The following table outlines the fluorescence properties of available iFluor® dye labeled anti-human CD34 antibodies for use in flow cytometry (FACS) and fluorescence imaging applications. Conjugates made with iFluor® dyes exhibit superior brightness and photostability, outperforming Alexa Fluor^® conjugates and other spectrally similar conjugates. For additional information on iFluor® dye-labeled CD34 antibodies and availability of other clones click on any label in the table below.

1. ε = molar extinction coefficient at their maximum absorption wavelength (Units = cm^-1M^-1).
2. Φ = fluorescence quantum yield in aqueous buffer (pH 7.2).
3. CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm (for oligo and nucleic acid labeling).
4. CF at 280 nm is the correction factor used for eliminating the dye contribution to the absorbance at 280 nm (for peptides and protein labeling).

mFluor™ Dyes Labeled to CD34 Antibodies

The following table outlines the fluorescence properties of available mFluor™ dye labeled anti-human CD34 antibodies for use in flow cytometry (FACS). Each mFluor™ dyes is optimally excited by one of the major laser lines commonly equipped in flow cytometers, such as the 405 nm, 488 nm, 532 nm, 561 nm or 633 nm laser lines. For additional information on mFluor™ dye-labeled CD34 antibodies and availability of other clones click on any label in the table below.

1. ε = molar extinction coefficient at their maximum absorption wavelength (Units = cm^-1M^-1).
2. Φ = fluorescence quantum yield in aqueous buffer (pH 7.2).
3. CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm (for oligo and nucleic acid labeling).
4. CF at 280 nm is the correction factor used for eliminating the dye contribution to the absorbance at 280 nm (for peptides and protein labeling).

Alexa Fluor^® Dyes Labeled to CD34 Antibodies

The following table outlines the fluorescence properties of available Alexa Fluor^® dye labeled anti-human CD34 antibodies for use in flow cytometry (FACS) and fluorescence imaging applications. For additional information on Alexa Fluor^® dye-labeled CD34 antibodies and availability of other clones click on any label in the table below.

1. ε = molar extinction coefficient at their maximum absorption wavelength (Units = cm^-1M^-1).
2. Φ = fluorescence quantum yield in aqueous buffer (pH 7.2).
3. CF at 280 nm is the correction factor used for eliminating the dye contribution to the absorbance at 280 nm (for peptides and protein labeling).

Classic Dyes Labeled to CD34 Antibodies

The following table outlines the fluorescence properties of available classic dye labeled anti-human CD34 antibodies for use in flow cytometry (FACS) and fluorescence imaging applications. For additional information on classic dye-labeled CD34 antibodies and availability of other clones click on any label in the table below.

1. ε = molar extinction coefficient at their maximum absorption wavelength (Units = cm^-1M^-1).
2. Φ = fluorescence quantum yield in aqueous buffer (pH 7.2).
3. CF at 280 nm is the correction factor used for eliminating the dye contribution to the absorbance at 280 nm (for peptides and protein labeling).

PE, APC, PerCP and Tandem Dyes Labeled to CD34 Antibodies

The following table outlines the fluorescence properties of available phcoerythrin (PE), allophycocyanin (APC), PerCP and tandem dye labeled anti-human CD34 antibodies for use in flow cytometry (FACS). Phycobiliproteins are uncharacteristically bright due to their high molar extinction coefficients and quantum yields, an enviable quality when imaging low-abundance targets. However, since phycobiliprotiens photobleach rapidly, they are not recommended for microscopy. For additional information on phycobiliprotein-labeled CD34 antibodies and availability of other clones click on any label in the table below.

1. ε = molar extinction coefficient at their maximum absorption wavelength (Units = cm^-1M^-1).

References

---

1. Ando, K. Human CD34? Hematopoietic Stem Cells: Basic Features and Clinical Relevance. Int J Hematol 75, 370-375 (2002). https://doi.org/10.1007/BF02982126
2. Lanza F, Healy L, Sutherland DR. Structural and functional features of the CD34 antigen: an update. J Biol Regul Homeost Agents. 2001;15(1):1?13.
3. NIELSEN, J.S. and MCNAGNY, K.M. (2009), CD34 is a Key Regulator of Hematopoietic Stem Cell Trafficking to Bone Marrow and Mast Cell Progenitor Trafficking in the Periphery. Microcirculation, 16: 487-496. doi:10.1080/10739680902941737.
4. Sassetti C, Van Zante A, Rosen SD. Identification of endoglycan, a member of the CD34/podocalyxin family of sialomucins. J Biol Chem. 2000;275(12):9001?9010. doi:10.1074/jbc.275.12.9001.