| Field | Specification |
|---|---|
| Target | |
| Alternative names | Cathepsin K;3.4.22.38;Cathepsin O;Cathepsin O2;Cathepsin X;CTSK;CTSO, CTSO2; |
| UniProt # | |
| Host | |
| Clonality | |
| Isotype | |
| Reactivity | |
| Applications | |
| Immunogen | E. coli-derived human Cathepsin K recombinant protein (Position: A115-M329). Human Cathepsin K shares 86.9% and 88.8% amino acid (aa) sequence identity with mouse and rat Cathepsin K, respectively. |
| Molecular weight | |
| Purification | |
| Reconstitution | |
| Cellular localization | |
| Concentration | |
| Form | Lyophilized |
| Storage | |
| Catalog no. (Mfr.) | |
| Main SKU |
Product Overview
This rabbit polyclonal antibody detects cathepsin K (gene CTSK) in human samples and is validated for IHC and Western blot. The predicted molecular weight is 37.0 kDa, and the supplier reports an observed band at about 45 kDa.
Cathepsin K (CTSK) is a cysteine protease secreted by osteoclasts that breaks down type I collagen in bone. It is the main collagenase driving bone resorption, and its loss causes pycnodysostosis, a condition of dense, brittle bone. It also helps release thyroid hormone from thyroglobulin and is studied in bone remodeling and osteoporosis.
| Target | Cathepsin K (gene CTSK; UniProt P43235, human) |
|---|---|
| Host / Clonality / Isotype | Rabbit / Polyclonal / Rabbit IgG |
| Reactivity | Human |
| Form | Lyophilized |
| Formulation | Per vial: 0.9 mg NaCl; 0.2 mg Na2HPO4; 0.05 mg NaN3; plus stabilizers |
| Calculated MW | 37.0 kDa |
| Observed MW | 45 kDa |
| Storage | As supplied: −20 °C for up to 12 months from receipt. After reconstitution: 4 °C for up to 1 month, or aliquot and keep at −20 °C for up to 6 months. Avoid repeated freeze–thaw cycles. |
Validated Applications
| IHC (paraffin sections) | 0.5–1 µg/mL (Human) |
|---|---|
| Western blot | 0.1–0.5 µg/mL (Human) |
Samples with a confirmed band (WB): HeLa cells, 22RV1 cells.
Recommended loading (WB): 20–40 µg of total protein per lane.
Conditions in the example images (WB): 5–20% gradient SDS-PAGE under reducing conditions, 30 µg lysate per lane, transfer to nitrocellulose membrane, blocking in 5% non-fat milk, primary antibody at 0.5 µg/mL overnight at 4 °C, HRP-conjugated secondary antibody at 1:5000, ECL detection.
Samples with confirmed staining (IHC): human osteosarcoma tissue.
Recommended antigen retrieval: heat-mediated, in TE buffer (pH 9.0); citrate buffer (pH 6.0) can be used instead.
Conditions in the example images (IHC): heat-mediated antigen retrieval in EDTA buffer (pH 8.0).
Immunogen
Recombinant human Cathepsin K fragment (Ala115–Met329), expressed in E. coli. Sequence identity with the mouse and rat orthologs: 86.9% and 88.8%, respectively.
Reactivity Notes
The supplier lists reactivity with human. UniProt describes cathepsin K as secreted and also located in the lysosome and apical cell membrane. Tissue expression noted by UniProt (human): Predominantly expressed in osteoclasts (bones). The samples tested by the supplier (listed above) are a practical starting point for positive controls.
Safety
Customization & Add-ons: Can’t find the antibody you need—or require a custom format for your assay? We can help you source the best match or support custom antibody solutions for diverse research needs, including species and isotype selection, conjugations and labeling (e.g., HRP/AP, biotin, fluorophores), purification grade options (Protein A/G, affinity purified), formulation preferences (buffer selection, carrier-free, glycerol-free), custom concentrations and aliquoting, low-endotoxin options for cell-based work, and application-focused QC/validation support (project dependent). Click Talk to a Scientist to submit a request, email us at support@biohippo.com, or explore our Research Services for additional support—our team will follow up with feasibility details and next steps.
Hantao Yao et al. (2023) Sulforaphene suppresses RANKL-induced osteoclastogenesis and LPS-induced bone erosion by activating Nrf2 signaling pathway. Free Radical Biology and Medicine. 10.1016/j.freeradbiomed.2023.07.009
Wenqian Fang et al. (2020) Cathepsin B deficiency ameliorates liver lipid deposition, inflammatory cell infiltration, and fibrosis after diet-induced nonalcoholic steatohepatitis. Translational Research. 10.1016/j.trsl.2020.04.011
Jiang Wang et al. (2017) Autocrine and paracrine STIP1 signaling promote osteolytic bone metastasis in renal cell carcinoma. Oncotarget. 10.18632/oncotarget.15222
Meng Sun et al. (2024) Extracellular vesicles derived from dental follicle stem cells regulate tooth eruption by inhibiting osteoclast differentiation. Frontiers in Cell and Developmental Biology. 10.3389/fcell.2024.1503481
Hantao Yao et al. (2025) Sulforaphene Mitigates Periodontitis by NRF2‐Dependent Regulation of P. gingivalis‐Induced Inflammatory Response and Bone Homeostasis. Food Science & Nutrition. 10.1002/fsn3.71319
Liu Yang et al. (2024) Integrated proteomics and metabolomics analysis of sclerosis-related proteins and femoral head necrosis following internal fixation of femoral neck fractures. Scientific Reports. 10.1038/s41598-024-63837-8
Yang Duan et al. (2019) PC-3-Derived Exosomes Inhibit Osteoclast Differentiation by Downregulating miR-214 and Blocking NF-B Signaling Pathway. Biomed Research International. 10.1155/2019/8650846
