Anti-human CD19 Monoclonal Antibodies for Flow Cytometry

PA007422.m2a: Non-conjugated Recombinant Anti-human CD19 Monoclonal Antibody (Clone: FMC63), Mouse IgG2a Kappa

Recombinant Mouse IgG2a Monoclonal Antibody. 
Clone: FMC63.
Isotype:  Mouse IgG2a kappa.
Source: The recombinant anti-human CD19 monoclonal antibody (clone: FMC63) was produced in mammalian cells.
Conjugation: Non-conjugated.
Specificity/Sensitivity: The recombinant FMC63 antibody specifically binds to the human CD19 protein.
Applications: Flow cytometry (FC), and Immunohistochemistry - Frozen (IHC-F). 
Form of Antibody: 0.2 uM filtered solution, pH 7.4, no stabilizers or preservatives.
Purity: >95% by SDS-PAGE under reducing conditions.

PA007422.h1Fs: Non-conjugated Recombinant Anti-human CD19 Monoclonal Antibody (Clone: FMC63), Human IgG1 Fc Silent Kappa

Recombinant human IgG1 monoclonal antibody with Fc silent mutation.
Clone: FMC63.
Isotype: Human IgG1 kappa.
Source: The recombinant anti-human CD19 monoclonal antibody (clone: FMC63) was produced in mammalian cells.
Conjugation: Non-conjugated.
Specificity/Sensitivity: The recombinant FMC63 antibody specifically binds to the human CD19 protein.
Applications: Flow cytometry (FC), and Immunohistochemistry - Frozen (IHC-F). 
Form of Antibody: 0.2 uM filtered solution, pH 7.4, no stabilizers or preservatives.
Purity: >95% by SDS-PAGE under reducing conditions.

PA007743.m2a-b: Biotinylated Recombinant Anti-human CD19 Monoclonal Antibody (Clone: FMC63), Mouse IgG2a Kappa

Recombinant mouse IgG2a monoclonal antibody with site-directed biotinylation through the Avi tag at the C-terminus of the antibody heavy chain.
Clone: FMC63.
Isotype:  Mouse IgG2a kappa.
Source: The site-directed biotinylated recombinant anti-human CD19 monoclonal antibody (clone: FMC63) was produced in mammalian cells.
Conjugation: Biotin-conjugated.
Specificity/Sensitivity: The site-directed biotinylated recombinant FMC63 antibody specifically binds to the human CD19 protein.
Applications: Flow cytometry (FC) with various dye conjugation through streptavidin; conjugation to streptavidin agarose beads or streptavidin magnetic beads.
Form of Antibody: 0.2 uM filtered solution, pH 7.4, no stabilizers or preservatives.
Purity: >95% by SDS-PAGE under reducing conditions.

Shipping: The FMC63 antibody is shipped with ice pack. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles. 
12 months from date of receipt, -20 to -70°C as supplied.
1 month from date of receipt, 2 to 8°C as supplied.

Background:

The FMC63 antibody binds to the human CD19 protein, a transmembrane protein expressed in all B lineage cells including human plasma cells. CD19 plays two major roles in human B cells: it acts as an adaptor protein to recruit cytoplasmic signaling proteins to the membrane, and works within the CD19/CD21 complex to decrease the threshold for B cell receptor signaling pathways. CD19 is a biomarker for B lymphocyte development, lymphoma diagnosis and can be utilized as a target for leukemia immunotherapies.

References of anti-human CD19 antibody (FMC63):

The costimulatory domain influences CD19 CAR-T cell resistance development in B-cell malignancies
Krawczyk, M., et al. (2025). bioRxiv [Preprint]. 2025 Mar 4:2025.02.28.640707. doi: 10.1101/2025.02.28.640707. PMID: 40093096
The FMC63 antibody (anti-human CD19) forms the basis of four approved CAR-T cell therapies for relapsed/refractory DLBCL and B-ALL. Epitope mapping identified key residues (W159, R163, K220, P222) encoded by exons 3 and 4, with R163 mutations disrupting the epitope. Flow cytometry using RTX with AlexaFluor 647-conjugated anti-Fc or anti-scFv (FMC63) antibody detected CAR-positive T-cells, while CD19 levels were monitored with HIB19 antibody post-tumor cell contact with CAR-T cells.
Tags: activity of FMC63 antibody; function of FMC63 antibody

Liquid biopsy approach to monitor the efficacy and response to CAR-T cell therapy
Shishido, S. N., et al. (2024). J Immunother Cancer. 2024 Feb 12;12(2):e007329. doi: 10.1136/jitc-2023-007329. PMID: 38350684
Autologous T cells engineered with anti-CD19 scFv based on FMC63 (anti-human CD19 antibody) were used to treat CD19+ B-cell malignancies. Proprietary reagents from Kite Pharma, including KIP-1, KIP-3, and CDL (anti-FMC63 scFv) mouse mAb, were used in CAR-T and B-cell assays. These assays employed DAPI for nuclei detection, anti-CD19 (FMC63), anti-CD19 (LE-CD19), and anti-CD20 (2H7) or anti-CD22 (S-HCL-1) antibodies to monitor therapy efficacy and CD19-negative relapse.
Tags: FMC63 antibody; FMC63 antibody for cancer research

IDR-induced CAR condensation improves the cytotoxicity of CAR-Ts against low-antigen cancers
Zhang, X., et al. (2023). bioRxiv [Preprint]. 2023 Oct 28:2023.10.02.560460. doi: 10.1101/2023.10.02.560460. PMID: 37873222
A CD19 CAR composed of FMC63 scFv (anti-human CD19), CD8α stalk and transmembrane domain, and cytosolic signaling domains (CD28, 41BB, CD3ζ) was analyzed. CAR expression on T cells was measured via flow cytometry using an anti-FMC63 antibody. Variants included intrinsically disordered regions (IDR) or coiled-coil domains, with superfolder GFP, enhancing cytotoxicity against low-antigen cancers.
Tags: FMC63 antibody for animal model; FMC63 antibody for flow cytometry

Inhibition of lactate transport by MCT-1 blockade improves chimeric antigen receptor T-cell therapy against B-cell malignancies
Lopez, E., et al. (2023). J Immunother Cancer. 2023 Jun;11(6):e006287. doi: 10.1136/jitc-2022-006287. PMID: 37399358
MCT-1 inhibition was studied with αCD19 CAR T cells (4-1BB co-stimulation) in NOD/SCID mice inoculated with 5×10^5 NALM-6 luciferase-expressing cells. OCR and ECAR were measured in αCD19-CAR T cells activated with plate-bound αFMC63 antibodies in the presence of MCT-1/2 blockers, demonstrating improved efficacy of FMC63-based (anti-human CD19) CAR T-cell therapy against B-cell malignancies.
Tags: FMC63 antibody mouse dose range; FMC63 antibody for mouse tumor model

Characterization of the input material quality for the production of tisagenlecleucel by multiparameter flow cytometry and its relation to the clinical outcome
Štach, M., et al. (2023). Pathol Oncol Res. 2023 Apr 20;29:1610914. doi: 10.3389/pore.2023.1610914. PMID: 37151356
CAR-T cells were identified using PE-conjugated CD19 protein initially, later replaced by anti-FMC63-FITC antibody (Acro Biosystems) for improved staining. Multiparametric flow cytometry with antibodies against CD3, CD4, CD8, CD14, CD45RA, CD62L, CD27, CD28, PD-1, and TIGIT analyzed apheresis material, CAR-T cell products, and post-administration blood samples to assess differentiation immunophenotype and clinical outcomes.
Tags: FMC63 mAb for mouse tumor model; FMC63 monoclonal antibody

For more references about anti-human CD19 antibody (FMC63), please contact our scientific support team with message@sydlabs.com.

Syd Labs provides the following in vivo grade recombinant anti-mouse CD19 monoclonal antibodies:
Recombinant Anti-mouse CD19 monoclonal antibody (Clone: 1D3)

Syd Labs provides the following in vivo grade recombinant anti-human CD19 monoclonal antibodies:
Recombinant Anti-human CD19 monoclonal antibody (Clone: SJ25C1)
Recombinant Anti-human CD19 monoclonal antibody (Clone: B43)
Recombinant Anti-human CD19 monoclonal antibody (Clone: FMC63)
Recombinant Anti-human CD19 monoclonal antibody (Clone: 4G7)

Syd Labs provides the following recombinant anti-mouse CD19 monoclonal antibodies for flow cytometry:
Recombinant Anti-mouse CD19 monoclonal antibody (Clone: 1D3) for flow cytometry

Syd Labs provides the following recombinant anti-human CD19 monoclonal antibodies for flow cytometry:
Recombinant Anti-human CD19 monoclonal antibody (Clone: SJ25C1) for flow cytometry
Recombinant Anti-human CD19 monoclonal antibody (Clone: FMC63) for flow cytometry
Recombinant Anti-human CD19 monoclonal antibody (Clone: B43) for flow cytometry
Recombinant Anti-human CD19 monoclonal antibody (Clone: 4G7) for flow cytometry