• Product name
    Anti-Yersinia pestis F1 antigen antibody [YPF19]
  • Description
    Mouse monoclonal [YPF19] to Yersinia pestis F1 antigen
  • Host species
  • Tested applications
    Suitable for: ELISA, WB, ICC/IFmore details
  • Species reactivity
    Reacts with Y. pestis. Does not react with Y. pseudotuberculosis and Y. enterocolitica. Not yet tested in otehr species.
  • Immunogen

    Purified F1 antigen from Y. pestis vaccine strain EB

  • General notes

    Abcam is committed to meeting high standards of ethical manufacturing and has decided to discontinue this product by June 2019 as it has been generated by the ascites method. We are sorry for any inconvenience this may cause.


  • Form
  • Storage instructions
    Shipped at 4°C. Upon delivery aliquot and store at -20°C. Avoid freeze / thaw cycles.
  • Storage buffer
    Preservative: 0.1% Sodium Azide
    Constituents: PBS, pH 7.4
  • Concentration information loading...
  • Purity
    Protein G purified
  • Purification notes
    >95% pure. Purity is tested by electrophoresis
  • Clonality
  • Clone number
  • Myeloma
  • Isotype
  • Research areas


Our Abpromise guarantee covers the use of ab20833 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 at an assay dependent dilution.
WB Use at an assay dependent dilution. Predicted molecular weight: 18 kDa. Dilution optimised using Chromogenic detection.
ICC/IF Use at an assay dependent dilution.


  • Relevance
    Yersinia pestis is a gram-negative coccobacillus belonging to the Enterobacteriaceae. Yersinia pestis is primarily a rodent pathogen, with humans being an accidental host when bitten by an infected rat flea.  The flea draws viable Y. pestis organisms into its intestinal tract. Some Y. pestis in the flea are then regurgitated when the flea gets its blood meal thus transferring the infection to a new host. While growing in the flea, Y. pestis loses its capsular layer, which is made of the F1 (or fraction 1) capsule antigen. Most of the organisms are phagocytosed and killed by the polymorphonuclear leukocytes in the human host. A few bacilli are taken up by tissue macrophages. The macrophages are unable to kill Y. pestis and provide a protected environment for the organisms to synthesize their virulence factors.
  • Cellular localization
  • Alternative names
    • Caf1 antibody
    • F1 capsule antigen antibody


This product has been referenced in:
See 1 Publication for this product

Customer reviews and Q&As


BATCH NUMBER 151645 ORDER NUMBER 124694 DESCRIPTION OF THE PROBLEM No signal. Does not react with purified F1 or the recombinant fusion protein, F1V SAMPLE purified F1 from E.coli and recombinant F1V isolated from E.coli inclusion body PRIMARY ANTIBODY After incubation with blocking buffer, washed the blot with 1 x 5 min with TBS, 1x10 min with TBS-Tween (TBST), 1x10 min with high salt buffer (HST - TBS with NaCl) Incubated with primary antibody -- F1 (ab20833) in HST for 1 hour RT. Used at 1:1000, 1:500 and then 1:100 Wash step-- 3x5 min with TBST and 1x5 min with HST DETECTION METHOD BCIP/NBT (Sigma) POSITIVE AND NEGATIVE CONTROLS USED positive control is purified Yersinia pestis F1 protein acquired from USAMRID (is not working, no signal) Negative control is purified V protein acquired froom USAMRID (no signal as expected) ANTIBODY STORAGE CONDITIONS 4 degrees, stored as it was instructed SAMPLE PREPARATION in TEAN (Tris HCl, EDTA, NaN3, NaCl) AMOUNT OF PROTEIN LOADED variable- 2ug to 20ug ELECTROPHORESIS/GEL CONDITIONS Reducing, Nupage 10% bis tris gel (invitrogen) TRANSFER AND BLOCKING CONDITIONS Nupage 20x transfer buffer (invitrogen) for 1 hour; Blocked with TBS, 0.1% tween-20 and 5% w/v nonfat dry milk for 1 hour room temperature (RT) or 4 C O/N SECONDARY ANTIBODY whole mouse IgG-AP conjugate [competitor] used at 1:4000 in HST and incubated for 1 hour at RT. Wash step -- 2x5 min TBST, 1x10 min HST, 1x5 min TBST, 1x5 min TBS HOW MANY TIMES HAVE YOU TRIED THE APPLICATION? 4 HAVE YOU RUN A "NO PRIMARY" CONTROL? No DO YOU OBTAIN THE SAME RESULTS EVERY TIME? Yes WHAT STEPS HAVE YOU ALTERED? Changed the dilution of primary antibody from 1:1000 to 1:100 ADDITIONAL NOTES the anti V monoclonal antibody works fine. does not react with purified F1 as expected. Previously, I was able to get some sera from mice injected with F1. I used the sera as a source of polyclonal F1 antibody to blot for my recombinant F1V and purified F1. It worked fine. But the monoclonal F1 never seems to work. Any thoughts? I

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Thank you for the details that you have provided and I'm sorry to hear that you are experiencing difficulty with ab20833. The antibody should absolutely detect purified Yersinia pestis F1 protein. I just need to check a few points; do you know that the protein transferred properly to the membrane? Is your secondary antibody working with other primary antibodies? Some suggestions that may help you are as follows. Try extending the incubation period with the primary to overnight at 4C. Also, try diluting the antibody in TBST only, this may help to enhance the signal. I would also recommend using ECL+ for detection as it is more sensitive than BCIP/NBT. I hope this helps. If not, I would be happy to provide you with a free of charge replacement or a refund or credit note.

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