|Detection of Rat CD19 by Western Blot. Western blot shows lysates of rat splenocytes. PVDF membrane was probed with 1 µg/mL of Mouse Anti-Rat CD19 Monoclonal Antibody (Catalog # MAB7489) followed by HRP-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # HAF018). Specific bands were detected for CD19 at approximately 60-110 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
|CD19 in Rat Spleen. CD19 was detected in perfusion fixed frozen sections of rat spleen using Mouse Anti-Rat CD19 Monoclonal Antibody (Catalog # MAB7489) at 25 µg/mL overnight at 4 °C. Tissue was stained using the NorthernLights™ 557-conjugated Anti-Mouse IgG Secondary Antibody (red; Catalog # NL007) and counterstained with DAPI (blue). Specific staining was localized to B-cells inside the germinal layers. View our protocol for Fluorescent IHC Staining of Frozen Tissue Sections.|
CD19 (also surface antigen B4 and Leu12) is a 95‑110 kDa member of the Immunoglobulin superfamily of molecules. It is expressed by B cells, and interacts with CD21 for the purpose of reducing the threshold of the antigen signal needed to with activate the BCR. CD19 ligation also promotes B cell:follicular dendritic cell (FDC) interaction and B cell proliferation in the FDC zone of the spleen. Mature rat CD19 is a 529 amino acid (aa) type I transmembrane glycoprotein (aa 19‑547). Based on mouse, it contains a 269 aa extracellular region (aa 19‑287) plus a 236 aa cytoplasmic domain. The extracellular region possesses two C2-type Ig-like domains (aa 20‑113 and 171‑271) and one utilized phosphorylation site at Ser225. The cytoplasmic domain contains five potential Tyr phosphorylation sites. There is one splice form that shows a two aa substitution after Gly489. Over aa 19‑287, rat CD19 shares 88% and 57% aa sequence identity with mouse and human CD19, respectively.