Anti-FAK (Ab-576 / 577) Antibody

This rabbit polyclonal antibody from Antibodies.com specifically recognizes Focal Adhesion Kinase (FAK, also known as PTK2) when phosphorylated at tyrosine residues 576 and 577. These two adjacent tyrosines sit within the activation loop of the FAK kinase domain, and their phosphorylation is a hallmark of catalytically active FAK following integrin engagement, growth factor stimulation, or mechanical stress. The reagent is supplied as an unconjugated antiserum at 100 µl per vial, intended for western blot and immunohistochemistry workflows on human, mouse, and rat samples.

The antibody is raised in rabbit and purified as a polyclonal reagent, giving broad recognition of the dual-phosphorylated activation-loop state across different experimental contexts. In western blot, the expected band migrates around 125 kDa, consistent with full-length FAK. In immunohistochemistry, it can be used to localize activated FAK at focal adhesions and invadopodia, supporting studies of cell adhesion, migration, mechanotransduction, and tumor invasion. The unconjugated format lets researchers pair the antibody with their preferred HRP, fluorescent, or biotin secondary detection system.

For western blot, working dilutions between 1:500 and 1:2000 are commonly used, depending on sample preparation and detection chemistry. For immunohistochemistry on formalin-fixed paraffin-embedded tissue, antigen retrieval in citrate buffer pH 6.0 followed by a polymer-HRP detection system generally yields strong cytoplasmic and membrane-proximal staining at sites of focal adhesion assembly. The vial should be stored refrigerated; for longer-term use, aliquot and freeze, protect from light, and avoid repeated freeze-thaw cycles to preserve activity. Each lot is validated by Antibodies.com for specificity toward the phosphorylated Y576/Y577 epitope and for low background on the recommended applications. For research use only.