Anti-Fluorescein antibody (ab19491)

Rabbit polyclonal Fluorescein antibody. Validated in WB, ELISA. Cited in 10 publication(s). Immunogen corresponding to chemical / Small Molecule.


  • Product name

  • Description

    Rabbit polyclonal to Fluorescein
  • Host species

  • Specificity

    Specific to Fluoresceine. No cross reactivity with immunoglobulin of any species.
  • Tested applications

    Suitable for: ELISA, WBmore details
  • Species reactivity

    Reacts with: Species independent
  • Immunogen

    Fluoresceine conjugated to KHL.


  • Form

  • Storage instructions

    Shipped at 4°C. Upon delivery aliquot and store at -20°C. Avoid freeze / thaw cycles.
  • Storage buffer

    pH: 7.20
    Preservative: 0.1% Sodium azide
    Constituent: 0.0268% PBS
  • Concentration information loading...
  • Purity

    Immunogen affinity purified
  • Purification notes

    Immunoaffinity chromatography
  • Clonality

  • Isotype

  • Research areas


Our Abpromise guarantee covers the use of ab19491 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.


  • Relevance

    Fluorescein is a fluorophore commonly used to label proteins - protein-fluorescein conjugates are not usually susceptible to precipitation. In addition to its relatively high absorptivity, excellent fluorescence quantum yield and good water solubility, fluorescein has an excitation maximum of 494 nm that closely matches the 488 nm spectral line of the argon-ion laser, making it an important fluorophore for confocal laser-scanning microscopy and flow cytometry applications. Its fluorescence is pH sensitive and is significantly reduced below pH 7. Fluorescein emits most strongly between 500 and 550 nm, but it has a relatively broad emission spectrum reaching to over 600 nm. Several derivatives of fluorescein are commonly used, including FITC (fluorescein isothiocyanate), carboxylates and succinimidyl esters.
  • Alternative names

    • FI antibody
    • FITC antibody
    • fluorescein isothyocianate antibody
    • fluorescyl antibody


This product has been referenced in:

  • Tamura T  et al. Rapid labelling and covalent inhibition of intracellular native proteins using ligand-directed N-acyl-N-alkyl sulfonamide. Nat Commun 9:1870 (2018). Read more (PubMed: 29760386) »
  • Yamazaki T  et al. Functional Domains of NEAT1 Architectural lncRNA Induce Paraspeckle Assembly through Phase Separation. Mol Cell 70:1038-1053.e7 (2018). Read more (PubMed: 29932899) »
See all 11 Publications for this product

Customer reviews and Q&As

1-2 of 2 Abreviews or Q&A


Thank you for your enquiry.

I am sorry to confirm that regrettablythese antibodies have not yet been tested and guaranteed in this type of ELISAcoating the antibody on theplate using protein A. They have been testedas detection antibodies in indirect ELISA only.

Also, although we produce many in-house antibodies, we obtain other antibodies from a wide range of sources. Therefore, comparison experiments between antibodieswill not often have been done.

If you wish to be more certain, I can suggest choosing the antibody that has been best characterized. By this I mean the antibody that has been tested in the most applications and has the most data available (on the datasheet).

I hope this will be helpful to you. Should you have any further questions please do not hesitate to ask.

Read More


The reactivity of ab19491 has not been tested against FAM, this polyclonal antibody has been tested and will react with DTAF ( a fluorescein derivative) in addition to FITC.

Read More

For licensing inquiries, please contact

Sign up