Tested Applications
| Positive WB detected in | A375 cells, HCT 116 cells, HuH-7 cells, HepG2 cells, MCF-7 cells |
| Positive IHC detected in | human hepatocirrhosis tissue Note: suggested antigen retrieval with TE buffer pH 9.0; (*) Alternatively, antigen retrieval may be performed with citrate buffer pH 6.0 |
| Positive IF/ICC detected in | MCF-7 cells, A431 cells |
Recommended dilution
| Application | Dilution |
|---|---|
| Western Blot (WB) | WB : 1:5000-1:50000 |
| Immunohistochemistry (IHC) | IHC : 1:500-1:2000 |
| Immunofluorescence (IF)/ICC | IF/ICC : 1:200-1:800 |
| It is recommended that this reagent should be titrated in each testing system to obtain optimal results. | |
| Sample-dependent, Check data in validation data gallery. | |
Product Information
21327-1-AP targets Cathepsin D in WB, IHC, IF/ICC, ELISA applications and shows reactivity with human, mouse samples.
| Tested Reactivity | human, mouse |
| Cited Reactivity | human, mouse, rat, pig, chicken, bovine |
| Host / Isotype | Rabbit / IgG |
| Class | Polyclonal |
| Type | Antibody |
| Immunogen |
CatNo: Ag15254 Product name: Recombinant human Cathepsin D protein Source: e coli.-derived, PET28a Tag: 6*His Domain: 59-412 aa of BC016320 Sequence: VPAVTEGPIPEVLKNYMDAQYYGEIGIGTPPQCFTVVFDTGSSNLWVPSIHCKLLDIACWIHHKYNSDKSSTYVKNGTSFDIHYGSGSLSGYLSQDTVSVPCQSASSASALGGVKVERQVFGEATKQPGITFIAAKFDGILGMAYPRISVNNVLPVFDNLMQQKLVDQNIFSFYLSRDPDAQPGGELMLGGTDSKYYKGSLSYLNVTRKAYWQVHLDQVEVASGLTLCKEGCEAIVDTGTSLMVGPVDEVRELQKAIGAVPLIQGEYMIPCEKVSTLPAITLKLGGKGYKLSPEDYTLKVSQAGKTLCLSGFMGMDIPPPSGPLWILGDVFIGRYYTVFDRDNNRVGFAEAARL Predict reactive species |
| Full Name | cathepsin D |
| Calculated Molecular Weight | 412 aa, 45 kDa |
| Observed Molecular Weight | 32 kDa, 48 kDa, 52 kDa |
| GenBank Accession Number | BC016320 |
| Gene Symbol | Cathepsin D |
| Gene ID (NCBI) | 1509 |
| RRID | AB_10733646 |
| Conjugate | Unconjugated |
| Form | Liquid |
| Purification Method | Antigen affinity purification |
| UNIPROT ID | P07339 |
| Storage Buffer | PBS with 0.02% sodium azide and 50% glycerol, pH 7.3. |
| Storage Conditions | Store at -20°C. Stable for one year after shipment. Aliquoting is unnecessary for -20oC storage. 20ul sizes contain 0.1% BSA. |
Background Information
CTSD (Cathepsin D) also named CPSD, belongs to the peptidase A1 family. It is ubiquitously expressed and is involved in proteolytic degradation, cell invasion, and apoptosis. Human CTSD is synthesized as a 52-kDa precursor that is converted into an active 48-kDa single-chain intermediate in the endosomes, and then into a fully active mature form, composed of a 28~32-kDa heavy chain and a 14-kDa light chain, in the lysosomes. It is a lysosomal acid protease found in neutrophils and monocytes and involved in the pathogenesis of several diseases such as breast cancer and possibly Alzheimer disease (PMID: 27114232, PMID: 30717773, PMID: 30051532).
Protocols
| Product Specific Protocols | |
|---|---|
| IF protocol for Cathepsin D antibody 21327-1-AP | Download protocol |
| IHC protocol for Cathepsin D antibody 21327-1-AP | Download protocol |
| WB protocol for Cathepsin D antibody 21327-1-AP | Download protocol |
| Standard Protocols | |
|---|---|
| Click here to view our Standard Protocols |
Publications
What published studies show
The anti-Cathepsin D (CTSD) antibody (Cat# 21327-1-AP) has accumulated 221 citations across high-impact journals including Nature Metabolism, Nature Neuroscience, Nature Communications, Autophagy, Molecular Cell, PNAS, Cell Reports, Advanced Science, and Cell Death & Disease. Research fields span autophagy and lysosomal biology, neurodegenerative diseases (Parkinson's, Alzheimer's, Huntington's), oncology, spinal cord injury, skin flap survival, metabolic disorders, inflammation, cardiovascular disease, infectious disease, and toxicology.
| Species | Application | Title |
|---|---|---|
Cell Metab ABCG2 is an itaconate exporter that limits antibacterial innate immunity by alleviating TFEB-dependent lysosomal biogenesis | ||
Cancer Commun (Lond) HMMR alleviates endoplasmic reticulum stress by promoting autophagolysosomal activity during endoplasmic reticulum stress-driven hepatocellular carcinoma progression | ||
Nat Metab mTORC1 regulates a lysosome-dependent adaptive shift in intracellular lipid species | ||
Bioact Mater Biomimetic stress granules replenish lysosomal repair to reinstate macrophage immunometabolic antibacterial programs. | ||
Nat Cell Biol Mitochondrial-derived vesicles drive budding-type fission of damaged lysosomes | ||
Nat Neurosci Mitochondrial accumulation and lysosomal dysfunction result in mitochondrial plaques in Alzheimer's disease |
Reviews
What customers say
All four reviews are 5-star ratings. Users report excellent performance of this cathepsin D antibody across multiple applications and sample types. It works well by Western blot at dilutions ranging from 1:3000 to 1:10000, successfully detecting the target in postmortem human brain lysates and TNBC cell line conditioned media. For immunofluorescence, it produces clear puncta staining in human fibroblasts (fixed in cold methanol) and iPSC-derived organoids at 1:100–1:200. Overall, reviewers highlight its strong sensitivity and reliable specificity across diverse tissues and species.
The reviews below have been submitted by verified Proteintech customers who received an incentive for providing their feedback.
Tae Yeon (Verified Customer) (09-02-2025) | Good puncta staining to detect lysosomal enzyme
|
aude (Verified Customer) (05-26-2025) | Sat 5% milk Incubation Primary Ab ON at 4°C
 |
Chen (Verified Customer) (06-01-2021) | Very good to detect cathepsin D in postmortem human samples with Western blotting
 |
Efil (Verified Customer) (05-29-2019) | cells were fixed in cold MeOH for 8 minutes
 |
