Flow cytometric analysis of fixed and permeabilized 293 cells (blue, negative) and Jurkat cells (green, positive) using CD45 (D9M8I) XP® Rabbit mAb (Alexa Fluor® 700 Conjugate) (solid lines) or a concentration-matched Rabbit (DA1E) mAb IgG XP® Isotype Control (Alexa Fluor® 700 Conjugate) #30720 (dashed lines).
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 700 fluorescent dye and tested in-house for direct flow cytometric analysis in human cells. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated CD45 (D9M8I) XP® Rabbit mAb #13917.
Supplied in PBS (pH 7.2), less than 0.1% sodium azide and 2 mg/ml BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.
All reagents required for this protocol may be efficiently purchased together in our Intracellular Flow Cytometry Kit (Methanol) #13593, or individually using the catalog numbers listed below.
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.
NOTE: When including fluorescent cellular dyes in your experiment (including viability dyes, DNA dyes, etc.), please refer to the dye product page for the recommended protocol. Visit www.cellsignal.com/flowdyes for a listing of cellular dyes validated for use in flow cytometry.
NOTE: Adherent cells or tissue should be dissociated and in single-cell suspension prior to fixation.
NOTE: Optimal centrifugation conditions will vary depending upon cell type and reagent volume. Generally, 150-300g for 1-5 minutes will be sufficient to pellet the cells.
NOTE: If using whole blood, lyse red blood cells and wash by centrifugation prior to fixation.
NOTE: Antibodies targeting CD markers or other extracellular proteins may be added prior to fixation if the epitope is disrupted by formaldehyde and/or methanol. The antibodies will remain bound to the target of interest during the fixation and permeabilization process. However, note that some fluorophores (including PE and APC) are damaged by methanol and thus should not be added prior to permeabilization. Conduct a small-scale experiment if you are unsure.
NOTE: Count cells using a hemocytometer or alternative method.
posted July 2009
revised August 2019
Protocol Id: 407
CD45 (D9M8I) XP® Rabbit mAb (Alexa Fluor® 700 Conjugate) recognizes endogenous levels of total CD45 protein.Species Reactivity:
Monoclonal antibody is produced by immunizing animals with recombinant protein specific to the carboxy terminus of human CD45 protein.
The protein phosphatase (PTP) receptor CD45 is a type I transmembrane protein comprised of a pair of intracellular tyrosine phosphatase domains and a variable extracellular domain generated by alternative splicing (1). The catalytic activity of CD45 is a function of the first phosphatase domain (D1) while the second phosphatase domain (D2) may interact with and stabilize the first domain, or recruit/bind substrates (2,3). CD45 interacts directly with antigen receptor complex proteins or activates Src family kinases involved in the regulation of T- and B-cell antigen receptor signaling (1). Specifically, CD45 dephosphorylates Src-family kinases Lck and Fyn at their conserved negative regulatory carboxy-terminal tyrosine residues and upregulates kinase activity. Conversely, studies indicate that CD45 can also inhibit Lck and Fyn by dephosphorylating their positive regulatory autophosphorylation site. CD45 appears to be both a positive and a negative regulator that conducts signals depending on specific stimuli and cell type (1). Human leukocytes including lymphocytes, eosinophils, monocytes, basophils, and neutrophils express CD45, while erythrocytes and platelets are negative for CD45 expression (4).
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Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
XP is a registered trademark of Cell Signaling Technology, Inc.
Alexa Fluor is a registered trademark of Life Technologies Corporation.
The Alexa Fluor dye conjugates in this product are sold under license from Life Technologies Corporation, for research use only excluding use in combination with DNA microarrays and high content screening (HCS).
This product is provided under an intellectual property license from Life Technologies Corporation. The transfer of this product is conditioned on the buyer using the purchased product solely in research conducted by the buyer, excluding contract research or any fee for service research, and the buyer must not (1) use this product or its components for (a) diagnostic, therapeutic or prophylactic purposes; (b) testing, analysis or screening services, or information in return for compensation on a per-test basis; or (c) manufacturing or quality assurance or quality control, and/or (2) sell or transfer this product or its components for resale, whether or not resold for use in research. For information on purchasing a license to this product for purposes other than as described above, contact Life Technologies Corporation, 5791 Van Allen Way, Carlsbad, CA 92008 USA or firstname.lastname@example.org.