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P4HB / Protein disulfide-isomerase · IHC design guide
Design Immunohistochemistry for P4HB
Plan chromogenic P4HB IHC in paraffin sections around the cytoplasmic staining reported in most tissues (HPA tissue IHC). Pancreatic exocrine glandular cells provide a high-staining reference (HPA tissue IHC); the catalog antibody A02335-1 lists 2–5 µg/mL for IHC (datasheet A02335-1).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
P4HB 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 staining in most tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic; high in pancreatic exocrine cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A02335-1) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Cerebellum+3 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Cell-surface P4HB may be shed in some cell types (UniProt) | |
| Regulation | No expression regulator specified (UniProt) | |
| Isoform / epitope | No isoforms listed; signal peptide 1–17 is processed (UniProt) |
Section 1
Recommended P4HB IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A02335-1) is followed by four published P4HB chromogenic IHC protocols (PMC9548632; PMC11304455; PMC6000295; PMC7751343).
| Sample | Paraffin-embedded mouse spleen tissue; fixative not specified (datasheet A02335-1) |
| Fixation | Image fixative and duration unreported (datasheet A02335-1); 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 A02335-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A02335-1) |
| Primary antibody | Rabbit anti-P4HB, 2-5μg/ml (datasheet A02335-1) |
| Primary incubation | Overnight at 4 °C (datasheet A02335-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A02335-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | P4HB-positive staining in endocrine cells of appendix (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A02335-1). Use citrate retrieval when reproducing the protocols that specify it (PMC11304455; PMC7751343).
Section 2
What Is the Expected P4HB Staining Pattern?
P4HB is principally an endoplasmic reticulum luminal protein with no transmembrane segment (UniProt P07237 topology). In paraffin-section IHC, expect cytoplasmic staining across most tissues (HPA: tissue IHC, Enhanced reliability), with high staining in pancreatic exocrine glandular cells, kidney proximal tubules and lung alveolar type II cells (HPA: High). Judge staining by both its cellular location and the annotated cell type.
| Cytoplasmic staining is strongest in pancreatic exocrine glandular cells or kidney proximal tubules. | This fits the reported high-staining cell populations (HPA: High in pancreatic exocrine glandular cells and kidney proximal tubules). An ER-associated distribution is consistent with P4HB's principal location (UniProt P07237; HPA: supported ER location in ICC-IF). Compare cells within the section before assigning an overall tissue score (standard IHC practice). |
| Predominantly nuclear staining, or uniform extracellular color, replaces the expected cytoplasmic pattern. | Treat this as a suspect result because tissue IHC reports cytoplasmic expression (HPA: tissue IHC profile). Review the counterstain and a no-primary control for detection artefact (standard IHC practice). A limited surface-associated pool is possible (UniProt P07237, Probable), so membrane staining alone is not decisive. |
| Strong staining appears in a cell population annotated as not detected, while an expected positive population is also present. | Consider cross-reactivity or endogenous detection activity, then check the no-primary control (standard IHC practice). For example, skeletal muscle myocytes are annotated not detected (HPA: skeletal muscle), but that annotation concerns those cells; it does not establish that every cell in a section must be negative. |
| Color is diffuse across tissue compartments and obscures cell boundaries. | This limits interpretation of the reported cytoplasmic pattern (HPA: tissue IHC profile). Background may arise from detection reagents, insufficient washing or nonspecific binding (standard IHC practice); the pattern by itself does not identify which step caused it. Compare a no-primary control before scoring cell-specific staining. |
| Pancreatic exocrine glandular cells show no interpretable staining. | They are reported as High (HPA: pancreas), so absence of signal warrants a workflow check before a biological conclusion. Examine section integrity, positive-control staining, retrieval, antibody dilution and detection steps (standard IHC practice). The supplied sources do not establish P4HB-specific fixation sensitivity. |
💡Expected P4HB appearanceCall a positive result when cytoplasmic staining is clear in high-reference cells such as pancreatic exocrine glandular cells (HPA: High; HPA: cytoplasmic tissue profile); diffuse color without cell-specific contrast is a suspect background pattern (standard IHC practice).
| Compartment and cell selection | P4HB is principally ER luminal and lacks a transmembrane segment (UniProt P07237 topology); HPA describes cytoplasmic expression in most tissues (HPA: tissue IHC profile). Select and score the named cell population, since an annotation such as High in kidney proximal tubules does not describe every kidney cell (HPA: kidney). |
| Strength of the tissue reference | The tissue profile has Enhanced reliability, described as high consistency between staining and RNA expression (HPA: tissue IHC). Two listed antibodies, HPA018884 and CAB012463, have Enhanced IHC status (HPA: antibodies). These observations support a reference pattern; they do not validate an unspecified catalog antibody or supply its working dilution. |
| Cell-surface interpretation | A secreted or plasma-membrane-associated pool is described for some cell types as Probable, with shedding and replacement from intracellular sources (UniProt P07237). Thus, a focal surface signal needs context; the main expected tissue-IHC pattern remains cytoplasmic (HPA: tissue IHC profile). Do not score broad membrane-only staining as the default positive pattern. |
| Reference-low and reference-negative cells | Cardiomyocytes and adipocytes are listed Low, while skeletal muscle myocytes and parathyroid glandular cells are Not detected (HPA: tissue IHC). These are cell-level comparisons, not universal negative-control guarantees. Check morphology and neighboring cell populations when comparing a slide with an HPA entry (standard IHC practice). |
| IF/ICC Q&A: Where should P4HB appear? | An ER distribution is the supported main ICC-IF location (HPA: subcellular). HPA lists images from A-431, U-251MG, U2OS and NIH 3T3 (HPA: subcellular). This supports a localization answer only; the supplied record gives no IF/ICC protocol option or IF working dilution. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in pancreatic exocrine glandular cells. | A high-reference population should be available for comparison (HPA: pancreas, High); the failed step cannot be identified from the blank slide alone. | Confirm tissue morphology and run a known-positive section through the same retrieval and detection workflow; review antibody dilution against its own documentation (standard IHC practice). |
| Strong color in the no-primary control. | Primary-antibody binding cannot explain color in that control; endogenous activity or detection-reagent background is possible (standard IHC practice). | Check the chromogenic detection controls and apply the blocking steps appropriate to the detection system (standard IHC practice); reassess the specimen before assigning P4HB-positive cells. |
| Uniform staining obscures cytoplasmic localization. | The slide cannot be confidently compared with the cytoplasmic tissue profile (HPA: tissue IHC); nonspecific binding or excess background is possible (standard IHC practice). | Review antibody concentration, blocking and wash steps, then compare with a no-primary control (standard IHC practice). Keep the expected cell distribution visible when adjusting conditions. |
| Nuclei stain more strongly than cytoplasm. | A dominant nuclear pattern conflicts with the reported cytoplasmic tissue expression and ER localization (HPA: tissue IHC and subcellular; UniProt P07237). | Check counterstain and detection controls, confirm cell boundaries, and repeat with a verified positive section if needed (standard IHC practice). |
| Only skeletal muscle myocytes appear positive. | Those myocytes are annotated Not detected (HPA: skeletal muscle). Cross-reactivity, background or mistaken cell identification should be considered; one slide cannot distinguish them. | Verify morphology, compare a no-primary control and inspect a high-reference cell population with the same staining run (standard IHC practice; HPA: pancreas, High). |
| Membrane staining dominates with little cytoplasmic signal. | Some surface association is described as Probable (UniProt P07237), but cytoplasmic expression is the tissue-IHC reference (HPA: tissue IHC profile). | Assess whether the signal tracks specific cells, compare controls and seek the expected cytoplasmic pattern in a high-reference population before calling the result typical (standard IHC practice; HPA: pancreas, High). |
Experiment evidence
IHC & IF images showing P4HB staining
A02335-1 · IHCIHC analysis of P4HB using anti-P4HB antibody (A02335-1). P4HB was detected in paraffin-embedded section of mouse spleen tissue. Heat mediat
A02335-1 · IHCIHC analysis of P4HB using anti-P4HB antibody (A02335-1). P4HB was detected in paraffin-embedded section of rat spleen tissue. Heat mediated
A02335-1 · IFIF analysis of P4HB using anti-P4HB antibody (A02335-1). P4HB was detected in immunocytochemical section of T-47D cells. Enzyme antigen retr
M02335-3 · IHCHuman breast carcinoma was stained with anti-PDI rabbit antibody
M02335-3 · IHCHuman liver was stained with anti-PDI rabbit antibody
M02335-2 · IFImmunofluorescent analysis using the Antibody at 1:50 dilution.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000185624-P4HB/tissue/cerebral+cortex#imid_5011636
HPA · DuodenumHuman Protein Atlas IHC, Duodenum. Source: https://www.proteinatlas.org/ENSG00000185624-P4HB/tissue/duodenum#imid_5011561
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000185624-P4HB/tissue/colon#imid_5011546
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000185624-P4HB/tissue/liver#imid_5011547
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA018884; green = P4HB, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA018884; green = P4HB, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for P4HB IHC & IF
🧪Run appendix first: its endocrine cells should stain strongly (HPA: appendix endocrine cells High). Use cerebellum granular-layer cells as the negative tissue (HPA: Not detected); on the appendix slide, compare endocrine cells with neighboring non-endocrine cells as a relative background reference, without assuming those cells lack P4HB (HPA: appendix endocrine cells High; UniProt P07237: highly abundant).
Positive control tissue: Appendix (Endocrine cells, HPA High)
Negative control tissue: Cerebellum (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show P4HB in A-431, U-251MG, U2OS, NIH 3T3, with annotated localisation: Endoplasmic reticulum (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; nonimmune rabbit IgG matched to the primary antibody’s immunoglobulin class and format where known (A02335-1 caption: rabbit primary); and P4HB knockout material as a biological negative, if available. On the appendix slide, quench endogenous peroxidase and check for endogenous biotin background because the documented detection uses a biotinylated secondary, streptavidin–biotin complex, and DAB (A02335-1 caption).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A02335-1 paraffin-section caption does not state the fixative. Heat retrieval in EDTA at pH 8.0 is a documented starting condition, but retrieval dependence is unreported (A02335-1 caption). Frozen-section performance and whether IF is easier are unreported; for appendix IHC, inspect luminal material and peroxidase or biotin background when interpreting staining (A02335-1 caption: biotin-based DAB detection).
HPA tissue IHC evidence for P4HB
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 | Endocrine cells | High | Protein (IHC) | HPA → |
| Colon | Endocrine cells | High | Protein (IHC) | HPA → |
| Duodenum | Endocrine cells | High | Protein (IHC) | HPA → |
| Epididymis | Glandular cells | High | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Parathyroid gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Skeletal muscle | Myocytes | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced P4HB IHC Tips
Troubleshoot P4HB staining by checking retrieval, compartment, cell identity, detection controls, and scoring against the validated IHC evidence.
Which retrieval conditions should I start with for P4HB paraffin IHC?
Start with heat-mediated antigen retrieval in EDTA, pH 8.0 (datasheet A02335-1). The catalog antibody detected P4HB in a paraffin-embedded mouse spleen section after this retrieval, followed by 2 µg/mL primary antibody overnight at 4°C (datasheet A02335-1). If staining is weak, compare retrieval duration on adjacent sections while keeping antibody concentration and DAB development constant (standard IHC practice). Include a tissue with a documented high-staining cell population, such as pancreatic exocrine glandular cells, to distinguish poor retrieval from a genuinely low signal in the study tissue (HPA: High in pancreatic exocrine glandular cells).
How should I assess whether fixation is suppressing P4HB staining?
Target-specific sensitivity to fixation is unknown because the selected paraffin-section caption does not state a fixative (datasheet A02335-1). Record the fixative and fixation time for each specimen, then compare sections processed together using the documented EDTA, pH 8.0 retrieval and 2 µg/mL primary antibody conditions (datasheet A02335-1; standard IHC practice). Use comparable tissue regions and the same DAB development time so processing differences remain interpretable (standard IHC practice). A control section containing pancreatic exocrine glandular cells provides a documented high-staining population, but its staining pattern alone cannot establish how fixation affects this antibody (HPA: High in pancreatic exocrine glandular cells).
What staining pattern is consistent with P4HB in chromogenic IHC?
Expect predominantly cytoplasmic staining in tissue sections, consistent with P4HB's supported endoplasmic reticulum localisation (HPA: cytoplasmic expression in most tissues; HPA: endoplasmic reticulum supported). P4HB is an endoplasmic reticulum lumen protein with no transmembrane segment, so assess whether signal occupies the cytoplasm around rather than inside nuclei (UniProt P07237 localisation and topology; standard IHC practice). Cell-surface association or secretion is reported as probable in some cell types, making a peripheral pattern possible but insufficient on its own to identify P4HB (UniProt P07237 subcellular annotation). Compare compartment and cell identity with adjacent morphology and a negative-control section before accepting unusually strong membrane or nuclear staining (standard IHC practice).
Could isoforms or epitope processing explain inconsistent P4HB staining?
The supplied record lists 0 isoforms, so an isoform-specific explanation is unsupported here (UniProt P07237 isoforms). P4HB has a signal peptide at residues 1–17 and a mature chain at 18–508; epitope interpretation depends on where the antibody binds, which the supplied caption does not specify (UniProt P07237 processing; datasheet A02335-1). Document the immunogen or mapped epitope if available before attributing a weak section to peptide processing (standard IHC practice). The record also lists modified residues, including phosphoserines at 331 and 357, but their effect on this antibody's tissue staining is unknown without an epitope map (UniProt P07237 modified residues).
How can IF help assess a P4HB IHC localisation result?
Use IF as a separate localisation check: P4HB is supported in the endoplasmic reticulum, and HPA has ICC/IF images in A-431, U-251MG, U2OS, and NIH 3T3 cells (HPA: subcellular; HPA: ICC/IF image list). For tissue multiplexing, pair P4HB with a validated marker of the expected cell type, such as pancreatic exocrine glandular cells in a pancreatic specimen, and assess signal within that population (HPA: High in pancreatic exocrine glandular cells; standard IF practice). Choose a fluorophore channel with low tissue autofluorescence and include single-label controls (standard IF practice). Permeabilise for an antibody epitope in the endoplasmic reticulum lumen, but verify epitope accessibility experimentally because its location is unspecified here (UniProt P07237 localisation; datasheet A02335-1; standard IF practice).
How do I reduce diffuse or misleading P4HB DAB background?
First separate widespread biological signal from technical background: P4HB is highly abundant and shows cytoplasmic expression in most tissues (UniProt P07237 subcellular annotation; HPA: tissue profile). The documented mouse spleen method used 10% goat serum blocking, 2 µg/mL primary antibody overnight at 4°C, a biotinylated secondary antibody, and DAB detection (datasheet A02335-1). Run a no-primary control and apply a peroxidase block as general chromogenic IHC controls; with biotin-based detection, check for endogenous biotin signal as well (standard IHC practice). If background persists, compare shorter DAB development or antibody concentration adjustments on adjacent sections while preserving the positive control (standard IHC practice).
How should I quantify P4HB staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and tissue region before scoring because HPA reports high staining in pancreatic exocrine glandular cells and kidney proximal tubule cell bodies, while several other populations are not detected (HPA: tissue IHC). For cell-based comparisons, record the percentage of positive cells and an intensity-based H-score using the same thresholds across slides (standard IHC practice). For spatial comparisons, count positive cells per mm² of viable, evaluable tissue and report the denominator explicitly (standard IHC practice). Normalise to the same cell type or compartment across samples, and keep retrieval, antibody concentration, DAB development, imaging, and counterstain consistent (standard IHC practice).
How can I distinguish convincing P4HB staining from artefact?
A convincing result matches cytoplasmic staining in a documented positive population, such as pancreatic exocrine glandular cells or lung alveolar type II cells (HPA: tissue IHC). Predominantly nuclear signal conflicts with the supported endoplasmic reticulum localisation, while an isolated membrane rim needs separate validation because cell-surface association is reported as probable in some cell types (HPA: subcellular; UniProt P07237 subcellular annotation). Compare suspicious staining with morphology, especially section edges and necrotic areas, and inspect a no-primary control for detection background (standard IHC practice). With DAB, rule out endogenous peroxidase and, for the documented biotin-based method, endogenous biotin before calling unexpected positive cells (datasheet A02335-1; standard IHC practice).
Boster reagents
Best P4HB / Protein disulfide-isomerase IHC Antibodies
Anti-P4HB antibodies have IHC images from human, mouse and rat tissues and IF images from human cells; the catalog also lists monkey reactivity for A02335-1 (catalog image captions; catalog reactivity).
Real IHC data
Anti-P4HB Antibody ®
Cat # A02335-1
Real IHC data
Anti-PDI Rabbit Monoclonal Antibody
Cat # M02335-3
Real IF data
Anti-P4HB Rabbit Monoclonal Antibody
Cat # M02335-2
A02335-1 has IHC images from mouse and rat spleen, human lymphoma and human renal clear cell carcinoma, plus IF in T-47D cells (A02335-1 image captions). M02335-3 has IHC images from human breast carcinoma, human liver and rat liver; M02335-2 has IF images with no sample identified (M02335-3 IHC captions; M02335-2 IF captions).
Which to pick: For paraffin-section IHC, start with A02335-1: its IHC captions specify heat retrieval in EDTA at pH 8.0, while the fixative is unreported (A02335-1 IHC captions). For IF/ICC, A02335-1 has an IF image in T-47D cells; M02335-2 is a rabbit monoclonal with IF images, but their captions do not identify the sample (A02335-1 IF caption; M02335-2 catalog and IF captions). For work spanning species, A02335-1 lists human, monkey, mouse and rat reactivity, although its IHC images show human, mouse and rat tissue only; M02335-3 offers rabbit monoclonal tissue IHC images from human and rat, with tissue processing and fixative unreported (A02335-1 catalog and IHC captions; M02335-3 catalog and IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P07237 (PDIA1_HUMAN, Protein disulfide-isomerase).
- Human Protein Atlas. P4HB tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. P4HB subcellular location (ICC-IF): Localized to the endoplasmic reticulum..
- Human Protein Atlas. P4HB antibody validation summary (2 antibodies).
- Identification and validation of P4HB as a novel autophagy-related biomarker in diabetic nephropathy. Frontiers in genetics 2022 — PMC9548632.
- The Role of P4HB and SOX4 in Prostatic Carcinoma and Their Clinical Significance. Iranian journal of pathology 2024 — PMC11304455.
- Prognostic value of hypoxia-inducible factor-1 alpha and prolyl 4-hydroxylase beta polypeptide overexpression in gastric cancer. World journal of gastroenterology 2018 — PMC6000295.
- P4HB: A novel diagnostic and prognostic biomarker for bladder carcinoma. Oncology letters 2021 — PMC7751343.
- PubMed PMID:3034602 — UniProt-cited evidence.
- PubMed PMID:3611107 — UniProt-cited evidence.
- PubMed PMID:2846539 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for P4HB (Protein disulfide-isomerase). Expected localisation Cytoplasmic staining in most tissues (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A02335-1). Validated IHC antibody: A02335-1 at 2-5μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Endocrine cells); negative Cerebellum. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse spleen tissue; fixative not specified (datasheet A02335-1); 2. Fixation: Image fixative and duration unreported (datasheet A02335-1); 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 A02335-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A02335-1); 8. Primary antibody: Rabbit anti-P4HB, 2-5μg/ml (datasheet A02335-1); 9. Primary incubation: Overnight at 4 °C (datasheet A02335-1). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Cell-surface P4HB may be shed in some cell types (UniProt); Isoform / epitope: No isoforms listed; signal peptide 1–17 is processed (UniProt); Regulation: No expression regulator specified (UniProt). Evidence: UniProt P07237, HPA tissue IHC · Enhanced, HPA ICC-IF · endoplasmic reticulum., Datasheet A02335-1, PMC9548632, PMC11304455. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/P4HB/immunohistochemistry-ihc-guide.