Fc Receptor Blocker

Fc receptors ( FcRs) are glycoproteins of approximate molecular weights of 50-70 kD. They are widely expressed throughout the immune cells. They are present on leukocytes such as monocytes, tissue macrophages, B cells, granulocytes (eosinophils, basophils, neutrophils), NK cells, and some T cells. Fc receptors are also present on mast cells, follicular dendritic cells, epithelial cells, endothelial cells, hepatocytes, and Langerhans cells among others.

There are several types of Fc receptors (FcR) that are classified based on the antibody that they recognize. There are those that have a great affinity for the Fc region of monomeric IgG antibody and are called Fc-Gamma receptors, those that bind to IgA antibody are called Fc-alpha receptors, and those that bind IgE antibody are called Fc-epsilon receptors.

Nonspecific Fc receptors staining in assays such as IHC, Immunofluorescence (IF), and flow cytometry can result from the binding of the Fc region of the primary and secondary antibody to the Fc receptors on the cells. Eliminating Fc receptor staining is desirable in IHC, IF, and Flow cytometry. For IHC testing:

The binding of the Fc region of the primary and/or the secondary antibody to the Fc receptors present on lymphoid tissues and other tissues containing Fc receptors gives rise to non-specific Fc receptor staining in Immunohistochemical (IHC) staining. Tissues rich in Fc receptors include lymphoid sections, lymphomas, tonsil, lymph nodes, bone marrow preparations, blood smears and tissues stained for most CD markers, Immunoglobulins (Igs), and Kappa and Lambda markers.

To avoid Fc receptor staining tissue sections are blocked with Innovex Fc Blocker for a short period prior to application of serum or protein blocking and especially prior to application of primary antibody (See instruction section of this datasheet).
For Flow cytometry assays: Fc receptors are present on leukocytes (white blood cells), many cell lines, and several other cell types in both human and animal tissues. Fc receptors give rise to non-specific

Fc receptor-staining in flow cytometry assays by binding of Fc region of antibodies and immunoglobulin (Igs) to Fc receptors on cells. Non-specific Fc receptors staining can be eliminated by blocking cells with INNOVEX Fc Blocker in a variety of Flow cytometry assays such as CD phenotyping, leukemia typing, and live-cell functional assays. (See instruction section of this datasheet).


Innovex Fc Receptor Blocker is a UNIVERSAL Fc Blocker applicable to Blocking all types of Fc receptors such as  Fc-gamma receptors of type I, II, and III; Fc -epsilon receptors type I and II; Fc –alpha receptors, Fc/R and FcRn.

Innovex Fc Blocker does NOT contain antibodies, Immunoglobulins, or immunoglobulin fragments.

INNOVEX Fc Blocker can be used to block all types of Fc receptors in all species including humans, mouse, and all-animal species cells and tissues by a variety of Immunoassays such as IHC, Immunofluorescence (IF), and Flow cytometry.

INNOVEX Fc Blocker is also commonly used in eliminating background staining in Brain cells/ tissues. MFC Receptor blocker is also used for obtaining specific staining for tissues stained for kappa, lambda antibodies, and Immunoglobulins (lgs) by IHC, IF and Flow cytometry assays.

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