CD34 is a glycosylated transmembrane protein and represents a well-known marker for primitive blood- and bone marrow-derived progenitor cells, especially for hematopoietic and endothelial stem cells. CD34+ stem cells are multipotent and can differentiate to all hematopoietic cell types in blood. CD34+ cells can also give rise to all lymphohematopoietic lineages even though they comprise only a small percentage of the cell population.

Our CD34+ cells are isolated using positive immunomagnetic cell separation procedures from single or mixed healthy donors. All cord blood is collected in Citric Phosphate with Dextrose Buffer (CPD) from fully consented IRB approved donors.

CD34 is a cluster of differentiation (CD) first described independently by Civin et al. and Tindle et al.[6][7][8][9] in a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells.

CD34是糖基化的跨膜蛋白，是原代血细胞和骨髓来源祖细胞（尤其是造血细胞）的典型表面标记。尽管CD34⁺细胞的功能现在还不清楚，但研究表明，CD34⁺细胞涉及维持造血祖细胞的未分化状态。北京金山科研平台生物技术有限公司（www.jinshanbio.com）提供健康供者来源的脐带血CD34⁺细胞。CD34⁺细胞适用于一系列研究，如直接诱导分化成各种相对成熟谱系血细胞。分选后的脐血CD34⁺细胞立即用无血清冻存液Cryostor CS10冻存，没有进行体外培养扩增，保持原代脐血CD34⁺细胞特性。每一支细胞提供完整的流式细胞检测报告。

Function of CD34 ：

The CD34 protein is a member of a family of single-pass transmembrane sialomucin proteins that show expression on early hematopoietic and vascular-associated tissue.[10] However, little is known about its exact function.[11]

CD34 is also an important adhesion molecule and is required for T cells to enter lymph nodes. It is expressed on lymph node endothelium, whereas the L-selectin to which it binds is on the T cell.[12][13] Conversely, under other circumstances CD34 has been shown to act as molecular "Teflon" and block mast cell, eosinophil and dendritic cell precursor adhesion, and to facilitate opening of vascular lumina.[14][15] Finally, recent data suggest CD34 may also play a more selective role in chemokine-dependent migration of eosinophils and dendritic cell precursors.[16][17] Regardless of its mode of action, under all circumstances CD34, and its relatives podocalyxin and endoglycan, facilitates cell migration.[10][16]

CD34 Tissue Distribution：

Cells expressing CD34 (CD34+ cell) are normally found in the umbilical cord and bone marrow as hematopoietic cells, or in mesenchymal stem cells, endothelial progenitor cells, endothelial cells of blood vessels but not lymphatics (except pleural lymphatics), mast cells, a sub-population dendritic cells (which are factor XIIIa-negative) in the interstitium and around the adnexa of dermis of skin, as well as cells in soft tissue tumors like dermatofibrosarcoma protuberans (DFSP), gastrointestinal stromal tumors (GISTs), solitary fibrous tumor (SFT), hemangiopericytoma (HPC), and to some degree in malignant peripheral nerve sheath tumors (MPNSTs), etc. The presence of CD34 on non-hematopoietic cells in various tissues has been linked to progenitor and adult stem cell phenotypes.[18]

It is important to mention that Long-Term Hematopoietic Stem Cells (LT-HSCs) in mice and humans are the hematopoietic cells with the greatest self-renewal capacity. Human HSCs express the CD34 marker.

CD34 is expressed in roughly 20% of murine hematopoietic stem cells,[19] and can be stimulated and reversed.[20]

CD34⁺细胞可以用于下游的实验研究

▪流式细胞分析

▪造血干细胞体外扩增

▪体外诱导造血分化研究

▪造血细胞重编程研究

▪逆转录病毒转导

▪基因表达分析

▪移植入人源化小鼠

Clinical applications：

CD34+ cells may be isolated from blood samples using immunomagnetic or immunofluorescent methods.

Antibodies are used to quantify and purify hematopoietic progenitor stem cells for research and for clinical bone marrow transplantation. However, counting CD34+ mononuclear cells may overestimate myeloid blasts in bone marrow smears due to B lymphocyte precursors and CD34+ megakaryocytes.

Cells observed as CD34+ and CD38- are of an undifferentiated, primitive form; i.e., they are multipotential hemopoietic stem cells. Thus, because of their CD34+ expression, such undifferentiated cells can be sorted out.

In tumors, CD34 is found in alveolar soft part sarcoma, preB-ALL (positive in 75%), AML (40%), AML-M7 (most), dermatofibrosarcoma protuberans, gastrointestinal stromal tumors, giant cell fibroblastoma, granulocytic sarcoma, Kaposi’s sarcoma, liposarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumors, meningeal hemangiopericytomas, meningiomas, neurofibromas, schwannomas, and papillary thyroid carcinoma.

A negative CD34 may exclude Ewing's sarcoma/PNET, myofibrosarcoma of the breast, and inflammatory myofibroblastic tumors of the stomach.

Injection of CD34+ hematopoietic Stem Cells has been clinically applied to treat various diseases including Spinal Cord Injury,[21] Liver Cirrhosis[22] and Peripheral Vascular disease.[23] Research has shown that CD34+ cells are relatively more in men than in women in the reproductive age among Spinal Cord Injury victims.[24]

数据：

相关产品：

▪CD34原代细胞

▪CD34造血干/祖细胞分离试剂盒

▪CD34造血干/祖细胞培养基和添加物

▪甲基纤维素半固体培养基

▪人G-CSF（#300-23）

▪ 人 SCF （#300-07）

▪ Flt3-ligand （# 300-19-2）

▪ 人IL-3 （#200-03）

▪人IL-6（#200-06）

▪人 TPO（#300-18）

▪CD34流式抗体

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