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CTNND1 / Catenin delta-1 · IHC design guide
Design Immunohistochemistry for CTNND1
Plan CTNND1 paraffin IHC around the cytoplasmic and membranous staining reported in most tissues (HPA tissue IHC). Start with 2–5 μg/ml of the IHC-validated antibody (datasheet A02333-3), and score cytoplasmic and cell-contact staining separately (UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CTNND1 Immunohistochemistry Experimental Design Guide
Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before staining
| Expected localisation | Cytoplasmic and membranous staining (HPA tissue IHC) | |
| Staining pattern | Most tissues show cytoplasmic and membranous staining (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A02333-3) | |
| Positive control | Placenta+4 more · see all | |
| Negative control | Caudate+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A02333-3) | |
| Caveat | Isoform shifts may affect epitope recognition (UniProt) | |
| Regulation | Isoform 4A is generally lost in SCC/melanoma cells (UniProt) | |
| Isoform / epitope | 32 isoforms may alter epitope coverage; no transmembrane segment (UniProt) |
Section 1
Recommended CTNND1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet: A02333-3) is paired with published renal allograft and lung tumor IHC protocols (PMC10464146; PMC10758022).
| Sample | Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet A02333-3) |
| Fixation | Image fixative and duration unreported (datasheet A02333-3); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A02333-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A02333-3) |
| Primary antibody | Rabbit anti-CTNND1, 2-5 μg/ml (datasheet A02333-3) |
| Primary incubation | Overnight at 4 °C (datasheet A02333-3) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A02333-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | CTNND1-positive staining in cytotrophoblasts of placenta (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and membranous expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet: A02333-3); the lung tumor study used EDTA but did not report its pH (PMC10758022).
Section 2
What Is the Expected CTNND1 Staining Pattern?
CTNND1 is expected mainly at cell membranes and cell–cell junctions, with cytoplasmic staining also reported; nuclear localization is possible in some contexts (UniProt O60716 localization). It has no transmembrane segment (UniProt O60716 topology). In paraffin tissue sections, expect staining in the cell populations identified by HPA, including placental cytotrophoblasts and testicular Sertoli cells (HPA: High in both). HPA rates its tissue IHC evidence Enhanced, with medium consistency between staining and RNA expression (HPA tissue IHC).
| Membranous staining outlines contacts between adjacent cells, with some cytoplasmic staining in the expected population. | This fits CTNND1 at adherens junctions and in the cytoplasm (UniProt O60716 localization). HPA describes cytoplasmic and membranous expression in most tissues (HPA tissue IHC). Judge the positive result by both its compartment and its cell type; a brown signal alone is insufficient. |
| Signal is predominantly nuclear, with little staining at cell contacts or in the cytoplasm. | Recheck compartment assignment and antibody specificity before calling this the expected IHC pattern (HPA tissue IHC: cytoplasmic and membranous profile). Nuclear CTNND1 remains biologically possible: UniProt reports nuclear localization and GLIS2-associated nuclear translocation by similarity (UniProt O60716 localization). An isolated nuclear result needs contextual support. |
| Strong staining appears chiefly in an HPA-listed undetected population, such as splenic red-pulp cells. | HPA reports those cells as Not detected (HPA: spleen, cells in red pulp). Consider antibody cross-reactivity or endogenous chromogenic activity; inspect a no-primary control and compare with an expected-positive population. An HPA negative is an observed result for that cell population, not proof that every specimen must be negative. |
| Brown precipitate spreads across cells and surrounding tissue without clear cell boundaries. | The distribution does not resolve the membranous or cytoplasmic pattern described by HPA (HPA tissue IHC). Assess nonspecific antibody binding, incomplete blocking or washing, and chromogen background as general IHC possibilities. Use the no-primary section to determine whether signal persists without the primary antibody. |
| Placental cytotrophoblasts or testicular Sertoli cells show no interpretable signal. | These are useful expected-positive populations because HPA reports High staining in each (HPA: cytotrophoblasts; HPA: Sertoli cells). First check that the named cells are present and preserved in the section. Then review the catalog antibody’s IHC-P instructions, reagent performance, and detection controls before interpreting absence as biological. |
💡Expected CTNND1 appearanceA convincing positive result shows clear membranous cell-contact staining, potentially with cytoplasmic signal, in expected cells such as strongly staining cytotrophoblasts or Sertoli cells (UniProt O60716 localization; HPA: High in both); broad cell-independent precipitate is suspect.
| Which compartments should guide scoring? | Prioritize cell contacts, membranes, and cytoplasm (UniProt O60716 localization; HPA tissue IHC). UniProt also lists the nucleus, so assess nuclear signal in context rather than treating every nuclear cell as an automatic false positive. |
| Does every tissue or cell type stain equally? | No. HPA reports High staining in placental cytotrophoblasts and Sertoli cells, Medium staining in colon endothelial cells, and Not detected in splenic red-pulp cells (HPA tissue IHC). Score the annotated cell population, not the whole organ. |
| How strong is the tissue-pattern evidence? | HPA labels tissue IHC Enhanced but describes only medium consistency between antibody staining and RNA expression (HPA tissue IHC). Its Enhanced IHC category reflects reproduction by independent antibodies or orthogonal data (HPA antibody validation); it does not guarantee every specimen will match. |
| Can isoforms change interpretation? | UniProt lists 32 CTNND1 isoforms and reports different isoform representation in keratinocytes, melanocytes, and melanoma cells (UniProt O60716 isoforms; tissue specificity). The supplied record gives no antibody epitope, so it cannot establish which isoforms the catalog antibody detects. |
| IF/ICC Q&A: where should fluorescent CTNND1 appear? | HPA reports mainly plasma-membrane localization, with an additional basal-body location in its ICC-IF data (HPA subcellular). This answers the compartment question for IF/ICC; use the separate IF/ICC guide for its experimental workflow. |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected-positive cells are present, but staining is absent. | A missed primary or detection step, weak reagents, or a mismatch with the catalog antibody’s IHC-P conditions are general workflow possibilities; HPA reports High staining in cytotrophoblasts and Sertoli cells (HPA tissue IHC). | Check an expected-positive section alongside the sample. Confirm antibody and detection steps against the catalog IHC-P instructions, then verify that the control produces a cell-localized signal. |
| All sections, including a no-primary control, develop brown signal. | Signal persisting without primary antibody points to endogenous detection activity or chromogen background as general IHC possibilities. | Check the detection chemistry and the relevant endogenous-activity block; compare the no-primary section with the test section before scoring CTNND1. |
| Signal is widespread and obscures cell borders. | Nonspecific binding, concentrated primary antibody, or inadequate washing can obscure the expected membranous and cytoplasmic profile (HPA tissue IHC). | Review blocking, primary-antibody concentration, and washes using the catalog IHC-P instructions; seek a localized pattern in the expected cells. |
| A negative cell population stains more strongly than the expected-positive cells. | Cross-reactivity or endogenous detection activity is possible. HPA reports some populations as Not detected, including splenic red-pulp cells (HPA tissue IHC). | Compare matched expected-positive and no-primary sections. Check the identity of the stained cells before assigning the signal to CTNND1. |
| Predominantly nuclear staining conflicts with the anticipated junctional pattern. | The result may reflect interpretation or specificity problems, although UniProt also lists nuclear localization and context-dependent translocation (UniProt O60716 localization). | Inspect cell boundaries and cytoplasmic signal, compare expected-positive tissue, and document the nuclear distribution rather than scoring it solely from color intensity. |
| Two tissues give different staining intensity. | That can fit the HPA record: placental cytotrophoblasts are High, colon endothelial cells are Medium, and splenic red-pulp cells are Not detected (HPA tissue IHC). | Identify and score the specific cell population in each tissue. Investigate technique only when an expected-positive population fails its control or loses interpretable localization. |
Experiment evidence
IHC & IF images showing CTNND1 staining
A02333-3 · IHCIHC analysis of delta 1 Catenin/CAS/CTNND1 using anti-delta 1 Catenin/CAS/CTNND1 antibody (A02333-3). delta 1 Catenin/CAS/CTNND1 was detecte
A02333-3 · IHCIHC analysis of delta 1 Catenin/CAS/CTNND1 using anti-delta 1 Catenin/CAS/CTNND1 antibody (A02333-3). delta 1 Catenin/CAS/CTNND1 was detecte
A02333-3 · IFIF analysis of delta 1 Catenin/CAS/CTNND1 using anti-delta 1 Catenin/CAS/CTNND1 antibody (A02333-3). delta 1 Catenin/CAS/CTNND1 was detected
M02333-2 · IHCIHC analysis of CTNND1 using anti-CTNND1 antibody (M02333-2). CTNND1 was detected in a paraffin-embedded section of human breast cancer tiss
M02333-2 · IHCIHC analysis of CTNND1 using anti-CTNND1 antibody (M02333-2). CTNND1 was detected in a paraffin-embedded section of human colorectal adenoca
M02333-2 · IFIF analysis of CTNND1 using anti-CTNND1 antibody (M02333-2). CTNND1 was detected in an immunocytochemical section of RT4 cells. Enzyme antig
M02333-4 · IHCRat liver was stained with anti-Catenin δ-1 rabbit antibody
M02333-4 · IHCHuman cervical squamous carcinoma was stained with anti-Catenin δ-1 rabbit antibody
M02333 · IFImmunofluorescent analysis of MCF-7 cells, using delta 1 Catenin/p120 Catenin Antibody .
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000198561-CTNND1/tissue/cerebral+cortex#imid_4082148
HPA · EsophagusHuman Protein Atlas IHC, Esophagus. Source: https://www.proteinatlas.org/ENSG00000198561-CTNND1/tissue/esophagus#imid_4082136
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000198561-CTNND1/tissue/colon#imid_4082074
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000198561-CTNND1/tissue/liver#imid_4082075
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA015955; green = CTNND1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA015955; green = CTNND1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CTNND1 IHC & IF
🧪Run placenta first: cytotrophoblasts should stain (HPA: High in placental cytotrophoblasts). Use caudate glial cells as the negative tissue (HPA: Not detected in caudate glial cells); on the placenta slide, assess background in cells outside the stained cytotrophoblast population without assuming those cells are CTNND1-negative (HPA: High in placental cytotrophoblasts).
Positive control tissue: Placenta (Cytotrophoblasts, HPA High)
Negative control tissue: Caudate (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CTNND1 in A-431, U-251MG, U2OS, ASC52telo, RPTEC/TERT1, hTERT-RPE1 (serum starved), with annotated localisation: Plasma membrane (enhanced) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a concentration-matched normal rabbit IgG control matched to the primary antibody’s clonality where known, and CTNND1-knockout material or a validated peptide-block control (selected-SKU caption: rabbit primary antibody). For placental sections, check endogenous peroxidase and biotin background when using the caption’s biotin–streptavidin/DAB detection system (selected-SKU caption: biotinylated secondary, SABC and DAB).
⚠️Feasibility: A target-specific fixation window and fixation effect are unreported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). The reported IHC example used heat retrieval in EDTA at pH 8.0, but retrieval dependence has not been established (selected-SKU caption: EDTA retrieval at pH 8.0). The supplied evidence does not establish whether frozen sections or IF are easier; for placental IHC, verify that apparent signal exceeds endogenous peroxidase or biotin background under the caption’s detection method (selected-SKU caption: SABC/DAB).
HPA tissue IHC evidence for CTNND1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Placenta | Cytotrophoblasts | High | Protein (IHC) | HPA → |
| Testis | Sertoli cells | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Hippocampus | Glial cells | Not detected | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Not detected | Protein (IHC) | HPA → |
| Vagina | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CTNND1 IHC Tips
Troubleshoot CTNND1 staining by checking retrieval, tissue handling, compartment pattern and cell identity before comparing staining intensity across paraffin sections.
Which retrieval condition should I start with for weak CTNND1 staining in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 for A02333-3 paraffin sections (datasheet A02333-3). The reported human liver cancer image used this retrieval condition, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A02333-3). If staining is weak, repeat retrieval with a controlled change in heating time while holding antibody concentration and detection constant (standard IHC practice). Include a matched positive tissue section and a no-primary control to distinguish poor epitope exposure from detection background (standard IHC practice). Inspect morphology alongside signal, because excessive heating can damage sections and complicate scoring (standard IHC practice).
Can fixation explain inconsistent CTNND1 staining between paraffin blocks?
Target-specific fixation sensitivity is unknown here: the A02333-3 tissue caption identifies a paraffin section but does not state its fixative (datasheet A02333-3). Record each block’s fixative and fixation duration before attributing an intensity difference to CTNND1 biology (standard IHC practice). Compare similarly processed sections in one staining run with the same pH 8.0 EDTA retrieval and antibody conditions (datasheet A02333-3; standard IHC practice). Uneven preservation, lost tissue or altered morphology can make a weak result difficult to interpret regardless of target (standard IHC practice). Use an independently documented positive control to check the staining run, while keeping fixation effects a testable possibility rather than a CTNND1-specific conclusion (standard IHC practice).
Should I score CTNND1 at cell borders, in cytoplasm or in nuclei?
Prioritize cell-border staining at adherens junctions, while documenting cytoplasmic and nuclear signal separately (UniProt O60716 subcellular location). In tissue IHC, HPA describes predominantly cytoplasmic and membranous expression across most tissues (HPA tissue IHC). CDH1 enhances CTNND1 membrane localization, and NANOS1 can shift it from cell contacts into cytoplasm (UniProt O60716 subcellular location). Nuclear localization is biologically possible, including GLIS2-associated translocation reported by similarity, but should receive its own compartment score (UniProt O60716 subcellular location; standard IHC practice). Check intact neighboring cells and a no-primary section before calling isolated nuclear or diffuse staining specific (standard IHC practice).
Could isoform choice or epitope accessibility change my CTNND1 IHC result?
CTNND1 has 32 listed isoforms, so antibody recognition cannot be assumed identical across splice variants without an epitope map (UniProt O60716 isoforms; standard IHC practice). Melanocytes and melanoma cells primarily express long isoform 1A, whereas keratinocytes favor shorter forms, especially 3A (UniProt O60716 tissue specificity). The C-terminal alternatively spliced exon B occurs in colon, intestine and prostate transcripts but is lost in several tumors from those organs (UniProt O60716 tissue specificity). Check whether the catalog antibody’s documented immunogen covers the isoforms relevant to the specimen before comparing cases (standard IHC practice). Interpret a negative stain cautiously when epitope coverage is undocumented, even if retrieval and controls perform well (standard IHC practice).
How should I assess CTNND1 localisation in a multiplex IF follow-up?
For an IF follow-up, pair CTNND1 with a marker of the expected cell type, such as an epithelial marker when assessing glandular cells, and identify nuclei with a counterstain (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores after examining an unstained section for tissue autofluorescence; a far-red channel may improve contrast where shorter wavelengths are bright (standard IF practice). CTNND1 has no transmembrane segment, so choose permeabilisation according to the documented antibody epitope and desired intracellular access (UniProt O60716 topology; standard IF practice). Compare junctional, cytoplasmic and nuclear compartments rather than combining them into one intensity value (UniProt O60716 subcellular location; standard IF practice). Validate channel bleed-through and background with single-stain and no-primary controls (standard IF practice).
How can I reduce diffuse or vascular background without masking CTNND1?
First compare the staining with a no-primary section and inspect whether signal follows tissue edges, vessels or damaged areas (standard IHC practice). CTNND1 is expressed in vascular endothelium, so vascular staining alone is not automatically background (UniProt O60716 tissue specificity). The A02333-3 tissue image used 10% goat serum blocking and 2 μg/ml primary antibody overnight at 4°C (datasheet A02333-3). Check endogenous peroxidase blocking and secondary reagent specificity before changing primary concentration in a DAB workflow (standard IHC practice). If diffuse color persists, titrate the primary antibody and development time against a matched positive section while preserving cell-border morphology (standard IHC practice).
What is a defensible way to quantify CTNND1 chromogenic staining? ⚠ ANSWER MARKED FOR VERIFICATION
Score the proportion of positive cells and intensity within a predefined cell population, then report a compartment-specific H-score on a 0–300 scale if intensity grading is reproducible (standard IHC practice). Record membranous, cytoplasmic and nuclear staining separately because CTNND1 can occupy each compartment (UniProt O60716 subcellular location). Normalize counts to the number of evaluable target cells, or express positive-cell density per mm² of viable tissue when cell counts are impractical (standard IHC practice). Keep retrieval, detection exposure and image thresholds consistent across compared sections (standard IHC practice). Exclude necrotic or detached areas and document the regions sampled before interpreting between-case differences (standard IHC practice).
When does a CTNND1-positive pattern suggest artefact rather than biology?
A convincing result shows staining in an anatomically plausible cell population with interpretable borders or cytoplasm, supported by appropriate controls (UniProt O60716 subcellular location; standard IHC practice). HPA reports high staining in placental cytotrophoblasts and testicular Sertoli cells, but its tissue IHC reliability is Enhanced with only medium RNA–staining consistency (HPA tissue IHC). Unexpected signal in another cell type therefore warrants review of morphology and a matched control rather than automatic rejection (standard IHC practice). Treat edge-restricted color, necrotic debris and signal reproduced in the no-primary section as artefact clues; check endogenous peroxidase in a DAB run (standard IHC practice). Interpret isolated nuclear staining cautiously, because nuclear CTNND1 is possible but should be distinguished from nonspecific color (UniProt O60716 subcellular location; standard IHC practice).
Boster reagents
Best CTNND1 / Catenin delta-1 IHC Antibodies
The catalog includes anti-CTNND1 antibodies with IHC images from human, mouse and rat tissues and IF images from human cells (catalog image captions).
Real IHC data
Anti-delta 1 Catenin/CAS/CTNND1 Antibody ®
Cat # A02333-3
Real IHC data
Anti-delta 1 Catenin/CAS/CTNND1 Antibody ® (monoclonal, 8G7E4)
Cat # M02333-2
Real IHC data
Anti-Catenin δ-1 Rabbit Monoclonal Antibody
Cat # M02333-4
Real IF data
Anti-delta 1 Catenin/p120 Catenin Rabbit Monoclonal Antibody
Cat # M02333
A02333-3 shows IHC in human liver cancer, mouse lung and intestines, and rat lung; M02333-2 shows IHC in human breast, colorectal and laryngeal cancers (catalog image captions). M02333-4 shows IHC in rat liver, human cervical and liver cancers, and mouse liver; M02333 shows IF in MCF-7 cells (catalog image captions).
Which to pick: For paraffin-section IHC, choose M02333-2 when a mouse monoclonal is preferred: its breast cancer IHC caption documents EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody (catalog image caption); the fixative is unreported (catalog image caption). For IF/ICC, M02333 has an MCF-7 IF image and lists both applications, with a listed IF dilution of 1:50 (catalog image caption; catalog applications and dilution). For IHC across species, A02333-3 has pictured human, mouse and rat paraffin sections prepared with EDTA retrieval at pH 8.0; its captions do not report the fixative (catalog image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O60716 (CTND1_HUMAN, Catenin delta-1).
- Human Protein Atlas. CTNND1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. CTNND1 subcellular location (ICC-IF): Mainly localized to the plasma membrane. In addition localized to the basal body..
- Human Protein Atlas. CTNND1 antibody validation summary (3 antibodies).
- Free apical surface hetero-cellular CDH1 homophilic binding is a major mediator of blastocyst-endometrium interaction in humans. Human reproduction (Oxford, England) 2026 — PMC13061149.
- Overexpression of CTNND1 in hepatocellular carcinoma promotes carcinous characters through activation of Wnt/β-catenin signaling. Journal of experimental & clinical cancer research : CR 2016 — PMC4872337.
- Glomerular proteomic profiling reveals early differences between preexisting and de novo type 2 diabetes in human renal allografts. BMC nephrology 2023 — PMC10464146.
- Anoikis-related CTNND1 is associated with immuno-suppressive tumor microenvironment and predicts unfavorable immunotherapeutic outcome in non-small cell lung cancer. Journal of Cancer 2024 — PMC10758022.
- PubMed PMID:9653641 — UniProt-cited evidence.
- PubMed PMID:9205841 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CTNND1 (Catenin delta-1). Expected localisation Cytoplasmic and membranous staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A02333-3). Validated IHC antibody: A02333-3 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Placenta (Cytotrophoblasts); negative Caudate. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet A02333-3); 2. Fixation: Image fixative and duration unreported (datasheet A02333-3); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A02333-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A02333-3); 8. Primary antibody: Rabbit anti-CTNND1, 2-5 μg/ml (datasheet A02333-3); 9. Primary incubation: Overnight at 4 °C (datasheet A02333-3). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A02333-3); Caveat: Isoform shifts may affect epitope recognition (UniProt); Isoform / epitope: 32 isoforms may alter epitope coverage; no transmembrane segment (UniProt); Regulation: Isoform 4A is generally lost in SCC/melanoma cells (UniProt). Evidence: UniProt O60716, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the plasma membrane. In addition localized to…, Datasheet A02333-3, PMC10464146, PMC10758022. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CTNND1/immunohistochemistry-ihc-guide.