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ERP29 / Endoplasmic reticulum resident protein 29 · IHC design guide
Design Immunohistochemistry for ERP29
Plan chromogenic IHC on paraffin sections using 2–5 μg/ml of the catalog antibody (datasheet A03621-2). Assess cytoplasmic staining in appendix glandular cells and bone marrow hematopoietic cells, with ovarian stromal cells as a low signal comparison (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ERP29 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 in tissue (HPA tissue IHC); ER lumen (UniProt) | |
| Staining pattern | Broad cytoplasmic staining across many cell types (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A03621-2) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Ovary |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A03621-2) | |
| Caveat | Ovarian stromal cells may be unstained (HPA tissue IHC) | |
| Regulation | Mostly expressed in secretory tissues (UniProt) | |
| Isoform / epitope | 2 isoforms; mature chain starts at residue 33; epitope dependence unknown (UniProt) |
Section 1
Recommended ERP29 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by three published ERP29 IHC protocols for osteosarcoma, nasopharyngeal carcinoma and gastric cancer (PMC6444297; PMC3583588; PMC5667996).
| Sample | Paraffin-embedded human prostate cancer tissue; fixative not specified (datasheet A03621-2) |
| Fixation | Image fixative and duration unreported (datasheet A03621-2); 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 A03621-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03621-2) |
| Primary antibody | Rabbit anti-ERP29, 2-5 μg/ml (datasheet A03621-2) |
| Primary incubation | Overnight at 4 °C (datasheet A03621-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A03621-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ERP29-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: Ubiquitous cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet A03621-2); citrate pH 6.0 is a published alternative for the osteosarcoma and nasopharyngeal carcinoma samples (PMC6444297; PMC3583588).
Section 2
What Is the Expected ERP29 Staining Pattern?
ERP29 is an endoplasmic reticulum lumen protein with no transmembrane segment (UniProt P30040 topology). In paraffin section IHC, expect cytoplasmic staining across many cell types, with particularly strong staining in several glandular, respiratory epithelial, hematopoietic, glial, and neuronal populations (HPA: ubiquitous cytoplasmic expression; High in the listed populations). HPA rates its tissue IHC reliability Enhanced, while reporting medium consistency between staining and RNA expression (HPA: tissue IHC reliability).
| Cytoplasmic chromogen in appendix or breast glandular cells, with a stronger signal than adjacent tissue. | This fits the reported compartment and cell types (HPA: ubiquitous cytoplasmic expression; High in appendix and breast glandular cells). Judge the identified cells, rather than treating every cell in the section as an equally strong positive. |
| Predominantly nuclear or sharply filamentous staining in an IHC section. | This is discordant with the expected tissue IHC pattern and merits an artefact or specificity check (HPA: ubiquitous cytoplasmic expression; UniProt P30040: ER lumen). HPA's separate ICC-IF observations are uncertain and do not establish that pattern for paraffin section IHC (HPA: subcellular ICC-IF). |
| Strong staining confined to ovarian stromal cells while expected positive cells remain unstained. | Consider cross-reactivity or endogenous detection activity before calling this ERP29 (HPA: ovarian stromal cells Not detected; general IHC practice). The HPA finding concerns stromal cells specifically; it does not make the whole ovary a negative tissue. |
| Even chromogen over cells, stroma, and empty areas, without a discernible cytoplasmic pattern. | This is background rather than an interpretable cell pattern (general IHC practice). Compare a no-primary control and review blocking, washing, and detection; HPA's cytoplasmic tissue pattern alone cannot identify the background source (HPA: tissue IHC profile). |
| No staining in appendix glandular cells or bronchial respiratory epithelial cells. | These are reported High populations, so an absent result calls for assay troubleshooting before a biological absence claim (HPA: High in appendix glandular and bronchial respiratory epithelial cells). Check that the relevant cells are present and that the positive control develops (general IHC practice). |
💡Expected ERP29 appearanceCall a positive result when identifiable cells show predominantly cytoplasmic chromogen, potentially strong in HPA High populations; isolated nuclear, stromal, or uniform background signal needs review (HPA: tissue IHC profile and listed levels; general IHC practice).
| Cell selection and intensity | HPA reports ubiquitous cytoplasmic expression but varying cell-level staining: High in breast glandular cells and bone marrow hematopoietic cells, Low in skeletal muscle myocytes and soft-tissue fibroblasts, and Not detected in ovarian stromal cells (HPA: tissue IHC). Use the named cell population when interpreting a section. |
| Compartment and processing | ERP29 is annotated in the ER lumen, lacks a transmembrane segment, and has a signal sequence at residues 1–32 with a mature chain at 33–261 (UniProt P30040: topology and processing). These annotations support a cytoplasmic ER-associated expectation; they do not identify an antibody epitope or predict paraffin-section retrieval sensitivity. |
| Antibody evidence and isoforms | Both listed antibodies have Enhanced IHC validation; HPA defines this as staining reproduced by independent antibodies or orthogonal data (HPA: HPA039363 and HPA039456 IHC validation). UniProt lists 2 isoforms (UniProt P30040: isoforms), but the supplied evidence does not establish which isoforms either antibody detects. |
| IF/ICC Q&A: should a microtubule pattern change the IHC call? | No. HPA describes microtubules as the main ICC-IF location and nucleoplasm as an additional location, both uncertain (HPA: subcellular ICC-IF). For paraffin section IHC, assess the reported cytoplasmic tissue pattern; the ICC-IF observation does not validate a nuclear or filamentous chromogenic result (HPA: tissue IHC profile). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive glandular or respiratory epithelial cells show no chromogen. | The run may have failed, or the expected cells may be absent from the sampled section (general IHC practice; HPA: High in appendix glandular and bronchial respiratory epithelial cells). | Confirm the cell population on the counterstained section, inspect the positive control, and review the antibody and detection steps (general IHC practice). Do not assign ERP29 absence from a failed run. |
| Signal is weak in a population reported High by HPA. | HPA levels describe its observed tissue staining, not a guaranteed intensity in every run (HPA: tissue IHC levels). Section and assay performance can affect an individual readout (general IHC practice). | Compare a concurrent known-positive section, then review the chosen antigen-retrieval and antibody conditions against the catalog IHC-P instructions (general IHC practice). No ERP29-specific retrieval effect is established here. |
| The dominant result is nuclear or filamentous staining. | The pattern conflicts with the expected cytoplasmic tissue profile; the separate microtubule and nucleoplasm ICC-IF calls are uncertain (HPA: tissue IHC profile; subcellular ICC-IF). | Check the positive-control pattern and no-primary control, then repeat with an IHC-validated antibody if needed (HPA: listed antibodies have Enhanced IHC validation; general IHC practice). |
| Ovarian stromal cells stain strongly. | That cell population is reported Not detected, so non-specific binding or endogenous detection activity is plausible (HPA: ovarian stromal cells Not detected; general IHC practice). | Verify stromal identity, compare a no-primary control, and review blocking and detection chemistry before interpreting the signal as ERP29 (general IHC practice). |
| Brown signal blankets the section or appears outside cells. | Diffuse deposition can obscure the expected cytoplasmic pattern (general IHC practice; HPA: ubiquitous cytoplasmic expression). | Compare the no-primary control, review washing and detection conditions, and score only localized cellular staining that remains distinguishable from background (general IHC practice). |
| A low-staining cell population is scored as a failed assay. | HPA reports Low staining in skeletal muscle myocytes and soft-tissue fibroblasts; faint signal there alone is an uncertain assay check (HPA: tissue IHC). | Use a reported High population as the positive comparator, such as appendix glandular cells or bone marrow hematopoietic cells, while scoring each cell type separately (HPA: tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing ERP29 staining
A03621-2 · IHCIHC analysis of ERP29 using anti-ERP29 antibody (A03621-2). ERP29 was detected in a paraffin-embedded section of human prostate cancer tissu
A03621-2 · IHCIHC analysis of ERP29 using anti-ERP29 antibody (A03621-2). ERP29 was detected in a paraffin-embedded section of human ovarian cancer tissue
A03621-2 · IFIF analysis of ERP29 using anti-ERP29 antibody (A03621-2). ERP29 was detected in an immunocytochemical section of HepG2 cells. Enzyme antige
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000089248-ERP29/tissue/cerebral+cortex#imid_9955476
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000089248-ERP29/tissue/colon#imid_9955410
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000089248-ERP29/tissue/liver#imid_9955403
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000089248-ERP29/tissue/kidney#imid_9955404
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA039456; green = ERP29, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA039456; green = ERP29, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ERP29 IHC & IF
🧪Run appendix first: glandular cells should stain (HPA: High in appendix glandular cells). Run ovary as the negative tissue, focusing on stromal cells (HPA: Not detected in ovarian stroma cells); on the appendix slide, any cells used as internal negatives should retain counterstain without specific DAB deposition, but their ERP29-negative status needs validation (standard IHC practice; UniProt P30040: ubiquitous expression).
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: Ovary (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ERP29 in A-431, U-251MG, U2OS, with annotated localisation: Microtubules (uncertain) (HPA subcellular).
Technical controls: Include a no-primary secondary-only control, a rabbit IgG isotype control matched to the primary antibody’s format, and an ERP29 knockout sample as a biological negative (caption: rabbit anti-ERP29; standard IHC practice). Quench endogenous peroxidase and inspect appendix glands for background DAB signal (standard chromogenic IHC practice).
⚠️Feasibility: The supplied evidence reports no target-specific fixation window or fixation effect; the selected A03621-2 paraffin-section caption does not state a fixative (selected-SKU caption). That caption uses EDTA at pH 8.0 for heat retrieval, but does not establish whether retrieval is required (selected-SKU caption). Neither frozen sections nor IF can be judged easier from the supplied evidence; for appendix, assess glandular luminal material and endogenous peroxidase as possible sources of misleading chromogenic signal (HPA: High in appendix glandular cells; standard IHC practice).
HPA tissue IHC evidence for ERP29
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 |
|---|---|---|---|---|
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Ovary | Ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced ERP29 IHC Tips
Troubleshoot ERP29 staining in paraffin sections by checking retrieval, tissue handling, cellular pattern, controls, and scoring before interpreting DAB signal.
What retrieval conditions should I start with for ERP29 in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A03621-2). The selected tissue image used that retrieval, followed by 10% goat serum and 2 μg/ml primary antibody overnight at 4°C (caption A03621-2). If staining is weak, compare retrieval duration or an alternative buffer on adjacent sections while keeping detection conditions constant (standard IHC practice). Assess tissue damage and background alongside signal, because stronger staining alone does not establish specificity (standard IHC practice). Record the chosen heat conditions so subsequent sections receive comparable treatment (standard IHC practice).
How should I assess whether fixation is affecting ERP29 staining?
The selected ERP29 tissue caption specifies a paraffin-embedded section but does not report its fixative, so target-specific fixation sensitivity is unknown (caption A03621-2). Compare sections with documented fixation histories using the same EDTA pH 8.0 retrieval and detection settings (datasheet A03621-2; standard IHC practice). Check morphology and staining across the section before attributing a weak result to fixation (standard IHC practice). Include a known staining tissue section processed alongside the test sections to reveal run-level problems (standard IHC practice). Do not infer fixation tolerance from ERP29 topology or tissue-expression patterns (UniProt P30040; HPA tissue IHC).
Where should convincing ERP29 DAB staining appear?
Expect a predominantly cytoplasmic cellular pattern in tissue IHC (HPA tissue IHC: ubiquitous cytoplasmic expression). An ER-associated distribution is biologically plausible because mature ERP29 resides in the ER lumen and has no transmembrane segment (UniProt P30040 localisation and topology). The HPA subcellular IF record also reports microtubules and nucleoplasm, but marks both assignments uncertain (HPA subcellular). Do not treat those uncertain IF locations as a required chromogenic tissue pattern (HPA subcellular; standard IHC interpretation). Compare staining with cell morphology and a negative-control section before calling isolated nuclear or extracellular DAB signal positive (standard IHC practice).
Could processing or isoforms change what this antibody detects in tissue?
ERP29 has 2 annotated isoforms and a signal peptide spanning residues 1–32; the annotated mature chain spans 33–261 (UniProt P30040 processing and isoforms). The supplied caption does not identify the antibody epitope, so neither isoform coverage nor recognition of the processed chain is established (caption A03621-2). ERP29 also has annotated phosphorylation at residues 64 and 66, with no annotated glycosylation sites (UniProt P30040 modified residues and glycosylation). If staining differs between samples, check epitope documentation before assigning the difference to an isoform or modification (standard IHC practice). Compare tissue patterns under identical retrieval and detection conditions first (standard IHC practice).
How can IF help assess an ambiguous ERP29 IHC pattern?
Use IF as a separate localisation check, rather than assuming the paraffin-section IHC conditions transfer directly (caption A03621-2; standard IF practice). Multiplex ERP29 with a marker for the cell type under examination and compare signals within the same cells (standard IF practice). Select fluorophores in channels with low tissue autofluorescence and include single-label controls to assess bleed-through (standard IF practice). Because ERP29 is annotated in the ER lumen without a transmembrane segment, test permeabilisation that permits antibody access to that compartment (UniProt P30040 localisation and topology; standard IF practice). Interpret microtubule or nucleoplasmic signals cautiously because the reported IF assignments are uncertain (HPA subcellular).
What should I change when DAB background obscures ERP29 staining?
First distinguish diffuse section-wide colour from cellular cytoplasmic staining, the reported ERP29 tissue pattern (HPA tissue IHC). The selected caption used 10% goat serum before 2 μg/ml primary antibody overnight at 4°C (caption A03621-2). Include a primary-omission control, block endogenous peroxidase, and review DAB development time to identify detection-related colour (standard chromogenic IHC practice). If background persists, titrate the primary antibody and reassess blocking while holding retrieval constant (standard IHC practice). Evaluate tissue edges and damaged areas separately, since their staining can mislead interpretation of the cellular pattern (standard IHC practice).
How should I score ERP29 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and cytoplasmic scoring compartment before measuring ERP29, consistent with its reported tissue pattern (HPA tissue IHC; standard IHC practice). For each region, report the percentage of positive cells and intensity, or combine them as an H-score using a fixed scoring rule (standard IHC practice). Where cell counts vary substantially, report positive cells per mm² and normalise to the relevant viable tissue area or eligible cell count (standard IHC practice). Use matched retrieval, exposure to DAB, and thresholds across compared sections (standard IHC practice). Record excluded necrotic and edge regions so the denominator remains auditable (standard IHC practice).
How do I distinguish genuine ERP29 positivity from staining artefacts?
A convincing result follows cellular cytoplasmic staining, the broad pattern reported for ERP29 in tissue (HPA tissue IHC). Compare the stained cell type with the section’s morphology; HPA reports high staining in several glandular populations and no detection in ovarian stroma cells (HPA tissue IHC). Treat isolated nuclear deposits cautiously because nucleoplasmic localisation was reported with uncertain confidence in IF (HPA subcellular). Check whether colour concentrates at section edges or necrotic areas, and whether it persists after omitting the primary antibody (standard IHC practice). If it does, investigate endogenous peroxidase and DAB background before scoring that colour as ERP29 (standard chromogenic IHC practice).
Boster reagents
Best ERP29 / Endoplasmic reticulum resident protein 29 IHC Antibodies
The IHC-validated antibody has paraffin-section images from human prostate cancer, ovarian cancer, spleen and thyroid cancer, plus IF images from HepG2 cells and human colon cancer sections (A03621-2 image captions).
Real IHC data
Anti-ERP29 Antibody ®
Cat # A03621-2
A03621-2 will render with its own human prostate cancer paraffin-section IHC figure; its catalog also shows IHC images from human ovarian cancer, spleen and thyroid cancer, and IF images from HepG2 cells and human colon cancer sections (A03621-2 image captions). M03621-1 is listed for IHC and ICC/IF in human, mouse and rat, but has no IHC or IF image caption in the payload and will not render as a card here (M03621-1 catalog entry; cards payload).
Which to pick: For tissue IHC, choose A03621-2 because its own caption documents paraffin-section staining with EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody; the fixative is unreported (A03621-2 IHC image caption). For IF/ICC, A03621-2 has image examples in HepG2 cells and human colon cancer sections, while monoclonal M03621-1, clone 18E73, lists ICC/IF without an image example here (A03621-2 IF image captions; M03621-1 catalog entry). For cross-species planning, A03621-2 lists human, monkey, mouse and rat reactivity, while M03621-1 lists human, mouse and rat; the supplied staining images for A03621-2 cover human samples only (catalog reactivity; A03621-2 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P30040 (ERP29_HUMAN, Endoplasmic reticulum resident protein 29).
- Human Protein Atlas. ERP29 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. ERP29 subcellular location (ICC-IF): Mainly localized to the microtubules. In addition localized to the nucleoplasm..
- Human Protein Atlas. ERP29 antibody validation summary (2 antibodies).
- Endoplasmic reticulum protein 29 (ERp29) as a novel prognostic marker and tumor suppressor in osteosarcoma. Journal of bone oncology 2019 — PMC6444297.
- Identification of ERp29 as a biomarker for predicting nasopharyngeal carcinoma response to radiotherapy. Oncology reports 2012 — PMC3583588.
- ERp29 inhibits tumorigenicity by suppressing epithelial mesenchymal transition in gastric cancer. Oncotarget 2017 — PMC5667996.
- Label-free quantitative mass spectrometry reveals a panel of differentially expressed proteins in colorectal cancer. BioMed research international 2015 — PMC4324820.
- PubMed PMID:9738895 — UniProt-cited evidence.
- PubMed PMID:16541075 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ERP29 (Endoplasmic reticulum resident protein 29). Expected localisation Cytoplasmic in tissue (HPA tissue IHC); ER lumen (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03621-2). Validated IHC antibody: A03621-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative Ovary. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human prostate cancer tissue; fixative not specified (datasheet A03621-2); 2. Fixation: Image fixative and duration unreported (datasheet A03621-2); 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 A03621-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03621-2); 8. Primary antibody: Rabbit anti-ERP29, 2-5 μg/ml (datasheet A03621-2); 9. Primary incubation: Overnight at 4 °C (datasheet A03621-2). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A03621-2); Caveat: Ovarian stromal cells may be unstained (HPA tissue IHC); Isoform / epitope: 2 isoforms; mature chain starts at residue 33 ; epitope dependence unknown (UniProt); Regulation: Mostly expressed in secretory tissues (UniProt). Evidence: UniProt P30040, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the microtubules. In addition localized to the…, Datasheet A03621-2, PMC6444297, PMC3583588. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ERP29/immunohistochemistry-ihc-guide.