• Product name
    Anti-VEGF Receptor 1 antibody [Flt-1/EWC]
    See all VEGF Receptor 1 primary antibodies
  • Description
    Mouse monoclonal [Flt-1/EWC] to VEGF Receptor 1
  • Host species
  • Specificity
    Detects native and denaturated VEGFR-1/ Flt-1
  • Tested applications
    Suitable for: ELISA, WB, ICC/IF, IHC-P, Flow Cytmore details
  • Species reactivity
    Reacts with: Mouse, Dog, Human
  • Immunogen

    Recombinant human soluble extracellular Flt-1 Ig-like loop 1 to 5 (sFlt-1(D5)).

  • Positive control
    • recombinant soluble VEGFR 1, soluble human VEGFR-1 from human follicular fluids (see Neulen et al), mouse placenta tissue
  • General notes

    VEGF and its high-affinity binding receptors, the tyrosine kinases FLK1 and FLT1, are thought to be important for the development of embryonic vasculature. It has been shown that an alternately spliced form of FLT1 produces a soluble protein, termed sFLT1, which binds vascular endothelial growth factor with high affinity. Because sFLT1 has a higher affinity for VEGF than does FLK1, it may function as an inhibitor of VEGF response.




Our Abpromise guarantee covers the use of ab9540 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
ELISA Use a concentration of 1 - 10 µg/ml.
WB Use a concentration of 2 - 5 µg/ml.
ICC/IF 1/50.
IHC-P Use at an assay dependent concentration. PubMed: 17823277
Flow Cyt Use at an assay dependent concentration. PubMed: 25223735


  • Function
    Receptor for VEGF, VEGFB and PGF. Has a tyrosine-protein kinase activity. The VEGF-kinase ligand/receptor signaling system plays a key role in vascular development and regulation of vascular permeability. Isoform SFlt1 may have an inhibitory role in angiogenesis.
  • Tissue specificity
    Mostly in normal lung, but also in placenta, liver, kidney, heart and brain tissues. Specifically expressed in most of the vascular endothelial cells, and also expressed in peripheral blood monocytes. Isoform sFlt1 is strongly expressed in placenta.
  • Sequence similarities
    Belongs to the protein kinase superfamily. Tyr protein kinase family. CSF-1/PDGF receptor subfamily.
    Contains 7 Ig-like C2-type (immunoglobulin-like) domains.
    Contains 1 protein kinase domain.
  • Cellular localization
    Secreted and Cell membrane.
  • Information by UniProt
  • Database links
  • Alternative names
    • EC antibody
    • FLT 1 antibody
    • FLT antibody
    • Flt-1 antibody
    • FLT1 antibody
    • Fms like tyrosine kinase 1 antibody
    • Fms related tyrosine kinase 1 antibody
    • Fms related tyrosine kinase 1 (vascular endothelial growth factor/vascular permeability factor receptor) antibody
    • Fms related tyrosine kinase 1 vascular endothelial growth factor/vascular permeability factor receptor antibody
    • Fms-like tyrosine kinase 1 antibody
    • FRT antibody
    • Soluble VEGF receptor 1 14 antibody
    • Soluble VEGFR1 variant 2 antibody
    • Soluble VEGFR1 variant 21 antibody
    • Tyrosine protein kinase FRT antibody
    • Tyrosine protein kinase receptor FLT antibody
    • Tyrosine-protein kinase FRT antibody
    • Tyrosine-protein kinase receptor FLT antibody
    • Vascular endothelial growth factor receptor 1 antibody
    • Vascular endothelial growth factor vascular permeability factor receptor antibody
    • Vascular permeability factor receptor 1 antibody
    • Vascular permeability factor receptor antibody
    • VEGFR 1 antibody
    • VEGFR-1 antibody
    • VEGFR1 antibody
    • VGFR1_HUMAN antibody
    see all


  • Anti-VEGF Receptor 1 antibody [Flt-1/EWC] (ab9540) + conditioned media from insect cells expressing recombinant mouse
    soluble VEGF Receptor 1
  • Immunohistochemistry analysis (Formalin/PFA-fixed paraffin-embedded sections) of Human Placenta, Placental Bed and Decidua Parietalis. VEGF Receptor 1 (geen) was labelled with ab9540 and VEGF Receptor 2 (red) was labelled with ab2349. Yellow - where both VEGF Receptor 1 and VEGF Receptor 2 are expressed. DAPI was used for nuclei staining (blue).

  • Immunofluorecent staining of human VEGF Receptor 1 in a co-culture of PAE-VEGF Receptor 1, PAE-KDR, and PAE-FLT-4 using ab9540. Goat anti-mouse ALEXA Flour at 1/6000 dilution was used as the secondary antibody.



This product has been referenced in:
  • Choi S  et al. RNA activating-double stranded RNA targeting flt-1 promoter inhibits endothelial cell proliferation through soluble FLT-1 upregulation. PLoS One 13:e0193590 (2018). Read more (PubMed: 29509796) »
  • Semba H  et al. HIF-1a-PDK1 axis-induced active glycolysis plays an essential role in macrophage migratory capacity. Nat Commun 7:11635 (2016). WB . Read more (PubMed: 27189088) »
See all 17 Publications for this product

Customer reviews and Q&As

1-5 of 5 Q&A


The binding epitope is located in ecto domain D1 or D2.

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We do not know if the antibody recognizes the receptor when bound with its ligand. We can confirm that the antibody recognizes the receptor unbound as the antibody will detect denaturated human VEGFR-1/ Flt-1 in ELISA experiments.

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We would like to confirm that this antibody recognizes both forms. IP is a normal standard protocol: 1-2µg antibody, 30µl anti-mouse IgG activated Sepharose beads (Sigma), incubation for 3-4 hours on a rotating dish or over night at 4°C. Centrifugation for 5min at 2.500rpm, aspire the supernatant and wash 3 times with TBST buffer. Reconstitute the beads in 2X SDS sample buffer or in other buffer you like.

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Yes, the soluble Flt-1(D1-5) was used for the immunization. This antibody recognizes very well the native soluble Flt-1 from e.g conditioned medium of HUVECs.

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Any commercial recombinant solube sVEGFR-1 will work (e.g. from RELIATech or R&D Systems). You can also use 5-10 ml CM from HUVEC and concentrate it by heparin affinity in order to get a nice band in Western blot.

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