United States (US)

Osteopontin antibody


Cat No. GTX28448

Host Rabbit
Clonality Polyclonal
Application WB, ICC/IF, IP, ELISA, IHC
Reactivity Human, Mouse, Rat, Dog, Pig

Application Note

*Optimal dilutions/concentrations should be determined by the researcher.
Application Dilution
WB 1:500 - 1:2000
ICC/IF Assay dependent
IP 1:100
ELISA 1:5000 - 1:20000
IHC 1:100 - 1:300
Not tested in other applications.

Calculated MW

35 kDa. ( Note )


Osteopontin is directed against human osteopontin. The antibody recognizes the full-length osteopontin protein (which runs at 66 kDa on westerns), as well as the C-terminal fragments of both thrombin and MMP-cleaved OPN. The 32 kDa MMP-cleaved C-fragment is recognized, but not the 40 kDa N-terminal fragment.




0.02 M Potassium Phosphate, 0.15 M Sodium Chloride, pH 7.2 and 0.01% (w/v) Sodium Azide


Store as concentrated solution. Centrifuge briefly prior to opening vial. For short-term storage (1-2 weeks), store at 4ºC. For long-term storage, aliquot and store at -20ºC or below. Avoid multiple freeze-thaw cycles.


82mg/ml(Please refer to the vial label for the specific concentration.)

Antigen Species



Peptide: CKSKKFRRPDIQYPD, also available as GTX29078.






For laboratory use only. Not for any clinical, therapeutic, or diagnostic use in humans or animals. Not for animal or human consumption.


Secreted Phosphoprotein 1,Bnsp,Bspi,Eta-1,Opn,Spp1

Cellular Localization



Osteopontin (OPN) is an arginine-glycine-aspartic acid (RGD)-containing glycoprotein that interacts with integrins and CD44 as major receptors (ref 1). OPN is multifunctional, with activities in cell migration, cell survival, inhibition of calcification, regulation of immune cell function, and control of tumor cell phenotype (ref 1-4). Targeting of the gene encoding OPN, spp1 , has revealed that while OPN is not necessary for normal embryonic development, fertility, and health under pathogen-free conditions (ref 5, 6), loss of the protein has significant consequences in several models of injury/disease as diverse as renal injury, viral and bacterial infection, bone remodeling, and tumor growth (ref 7-12). The fact that no other proteins seem to share a redundant activity with OPN under these conditions suggests that OPN has a unique functional role during tissue injury and stress. Interestingly, several members of the matrix metalloproteinase (MMP) family are also induced during injury/disease processes in patterns overlapping that of OPN (ref 13). OPN has recently been shown to be a novel substrate for two MMPs, MMP-3 (stromelysin-1) and MMP-7 (matrilysin) (ref 14). There are three cleavage sites for MMP-3 in human OPN, two of which are also cleaved by MMP-7 (see cleavage diagram). Biological assays demonstrate that the MMP-cleaved OPN has increased activity in promoting both cell adhesion and migration compared with full-length OPN. In addition, using inhibitory reagents, it was shown that the same receptors that interact with OPN also mediate interaction of MMP-cleaved OPN with tumor cells, suggesting that active forms of OPN at sites of tissue injury may be regulated by the activity of proteases including MMPs and that the differences in activity of modified OPN may be explained by differences in binding affinity of integrins or distinct downstream signaling events (ref 14).


Research Area


GTX28448 IHC Image

Rabbit anti-Osteopontin (GTX28448) was used at a 1:100-1:300 dilution to detect osteopontin by immunohistochemistry. Osteopontin is a normal component of elastic fibers in the breast (shown heavily stained in this section of human breast tumor cells). There is also weak staining of the extracellular matrix. Osteopontin is not expressed in breast tumor cells, and there is no staining of the breast cells in this section. No antigen retrieval is required


GTX28448 Image

OPN is cleaved by MMP to yield 2 fragments, which migrate at 40 kDa (N terminal) and 32 kDa (C terminal). The C terminal fragment can undergo further cleavage by both of these MMPs. The epitope that is recognized by Rabbit-anti-Osteopontin (GTX28448) is shown in violet. This antibody detects the full length OPN and the 32 kDa fragment. It does not recognize the 40 kDa fragment.

Package List Price ($)
$ 439