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IRF7 / Interferon regulatory factor 7 · IHC design guide
Design Immunohistochemistry for IRF7
Use the IHC-validated antibody at 2–5 μg/ml to assess IRF7 in paraffin sections (datasheet A00115-3). Score nuclear staining against the tissue pattern and consider activation-dependent nuclear accumulation when interpreting results (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
IRF7 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 | Nuclear staining in most tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in most tissues; distinct in lymphatic organs (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A00115-3) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent across samples. (standard IHC practice; not target-specific) | |
| Caveat | Activation can shift IRF7 from cytoplasm to nucleus (UniProt) | |
| Regulation | Viral/TLR signaling activates IRF7 (UniProt) | |
| Isoform / epitope | 4 isoforms (A–D); check epitope coverage before isoform scoring (UniProt) |
Section 1
Recommended IRF7 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A00115-3) is accompanied by published IRF7 IHC methods from 3 articles (PMC6423323; PMC11759022; PMC10876010).
| Sample | Paraffin-embedded human spleen tissue; fixative not specified (datasheet A00115-3) |
| Fixation | Image fixative and duration unreported (datasheet A00115-3); 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 A00115-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A00115-3) |
| Primary antibody | Rabbit anti-IRF7, 2-5 μg/ml (datasheet A00115-3) |
| Primary incubation | Overnight at 4 °C (datasheet A00115-3) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A00115-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | IRF7-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in most tissues, distinct expression in lymphatic organs. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 for the catalog antibody (datasheet A00115-3). For mouse striatum, citrate pH 6.0 is published (PMC11759022).
Section 2
What Is the Expected IRF7 Staining Pattern?
IRF7 staining is expected mainly in nuclei across many tissues, with distinct expression in lymphatic organs (HPA tissue IHC). Cytoplasmic staining can also be biologically plausible: IRF7 is a protein without a transmembrane segment, and its phosphorylated active form accumulates selectively in nuclei (UniProt Q92985). Interpret signal by cell type: HPA reports high staining in bone marrow hematopoietic cells and several epithelial and other cell populations, with medium consistency between staining and RNA data (HPA tissue IHC: Approved).
| Nuclear staining in identifiable cells, especially bone marrow hematopoietic cells; adjacent cells may vary in intensity. | This fits the predominantly nuclear tissue pattern and a reported high-staining cell population (HPA tissue IHC). Compare compartments and cell types within the section before calling a positive result; the Approved tissue profile has medium consistency with RNA data (HPA tissue IHC). |
| Predominantly cytoplasmic staining with little nuclear signal in a sample expected to show the tissue IHC pattern. | Review the pattern before calling it artefact. Cytoplasmic inactive IRF7 is plausible, whereas active phosphorylated IRF7 accumulates in nuclei (UniProt Q92985). HPA also supports cytosolic signal in ICC-IF (HPA subcellular). Cytoplasm alone does not establish activation or prove staining failure. |
| Strong signal appears in an unexpected cell population, or acellular material stains as intensely as the cells. | Check morphology and controls for cross-reactivity or endogenous chromogenic activity (general IHC practice). HPA reports high staining in diverse cell populations, including adipocytes, glia and epithelial cells; an unfamiliar positive cell type is therefore a reason to investigate, not grounds for automatic rejection (HPA tissue IHC). |
| A diffuse wash of chromogen obscures nuclei and cell boundaries across the section. | The compartment cannot be scored reliably. Review the negative control and detection background, then adjust blocking, antibody dilution or washing as appropriate for the assay (general IHC practice). A uniform haze is less informative than the cell-associated nuclear pattern described for IRF7 (HPA tissue IHC). |
| No cellular signal appears in bone marrow hematopoietic cells used as a positive tissue check. | HPA reports high staining in this population, so a blank result warrants review of tissue identity, antibody concentration, retrieval, detection reagents and run controls (HPA tissue IHC; general IHC practice). A failed run cannot establish that IRF7 is absent from the test specimen. |
💡Expected IRF7 appearanceCall a convincing positive when identifiable cells show predominantly nuclear chromogen, with clear high staining in a reported positive population such as bone marrow hematopoietic cells (HPA tissue IHC: High); diffuse acellular color or equally strong staining in every compartment calls for control review (general IHC practice).
| Compartment and activation | IRF7 can reside in cytoplasm and nucleus; its phosphorylated active form accumulates selectively in nuclei (UniProt Q92985). Nuclear enrichment is compatible with activation, but localisation alone does not measure phosphorylation (general IHC interpretation). |
| Tissue and cell selection | HPA describes nuclear expression in most tissues and distinct expression in lymphatic organs; it reports high staining in bone marrow hematopoietic cells and low staining in prostate glandular cells (HPA tissue IHC). Use the stated cell population when comparing sections; low is not negative. |
| Antibody evidence | HPA052757 and CAB017694 are IHC Approved; HPA052757 is also ICC Supported (HPA antibodies). The tissue profile is Approved with medium staining-to-RNA consistency (HPA tissue IHC). These labels support pattern review but do not make every unexpected cell signal specific. |
| Isoforms and modifications | UniProt lists four IRF7 isoforms and phosphorylation sites, including residues 471, 472, 475 and 477 (UniProt Q92985). The supplied record gives no antibody epitope or isoform coverage, so staining cannot identify an isoform or modification without separate validation. |
| IF/ICC Q: Where should IRF7 fluorescence appear? | A: Mainly in the nucleoplasm, with additional cytosolic signal (HPA subcellular: supported). HPA lists HEK293, PC-3 and U2OS ICC-IF images and marks HPA052757 ICC Supported (HPA subcellular; HPA antibodies). These IF observations guide localisation only; this section specifies no IF/ICC protocol. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in the test section or the bone marrow positive check. | The positive check conflicts with reported high staining in hematopoietic cells (HPA tissue IHC); a run or specimen problem remains possible (general IHC practice). | Verify the positive cell population and run controls. Review antigen retrieval, primary antibody dilution and chromogenic detection against the IHC-validated antibody's instructions (general IHC practice); do not infer IRF7 absence from a failed check. |
| Only cytoplasmic color appears where a nuclear pattern was expected. | Cytoplasmic IRF7 can be real, but HPA describes predominantly nuclear tissue staining (UniProt Q92985; HPA tissue IHC). | Inspect nuclear counterstain and cell boundaries, compare a positive tissue and negative control, and score nuclear and cytoplasmic signal separately (general IHC practice). Do not call cytoplasmic staining alone proof of antibody failure. |
| Strong staining extends through cells or acellular areas and hides morphology. | Diffuse chromogen may reflect nonspecific antibody or detection background (general IHC practice). | Examine the negative control; review blocking, primary antibody dilution, washing and detection timing according to the assay controls (general IHC practice). Reassess only where cell boundaries and nuclear localisation remain visible. |
| Unexpected cells stain strongly, including cells in a tissue with a lower reported level. | HPA records low staining in prostate glandular cells, but its broader profile includes many high-staining populations (HPA tissue IHC). Cross-reactivity or endogenous detection activity is possible (general IHC practice). | Identify the stained cell type morphologically and compare negative controls and a reported positive population before judging specificity (general IHC practice). Treat a low HPA level as context, not a universal negative control (HPA tissue IHC). |
| The positive pattern differs between tissue regions or specimens. | HPA reports cell-specific staining across tissues and medium consistency between antibody staining and RNA expression (HPA tissue IHC). Mixed cell populations can change the apparent pattern (general IHC interpretation). | Score the named cell population and nuclear versus cytoplasmic signal separately; compare equivalent regions and the same run controls (general IHC practice). Avoid converting a whole-section average into a cell-specific claim. |
| Nuclear staining is being reported as proof of phosphorylated IRF7. | Active phosphorylated IRF7 selectively accumulates in nuclei, but nuclear localisation does not identify a modification site (UniProt Q92985; general IHC interpretation). | Report nuclear enrichment as a localisation observation. Reserve a phosphorylation claim for a separately validated modification-specific assay; the supplied antibody evidence does not establish such specificity (HPA antibodies). |
Experiment evidence
IHC & IF images showing IRF7 staining
A00115-3 · IHCIHC analysis of IRF7 using anti-IRF7 antibody (A00115-3). IRF7 was detected in a paraffin-embedded section of human spleen tissue. Heat medi
M00115 · IHCImmunohistochemical analysis of paraffin-embedded human pancreas, using IRF7 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000185507-IRF7/tissue/cerebral+cortex#imid_4490124
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000185507-IRF7/tissue/colon#imid_4490058
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000185507-IRF7/tissue/liver#imid_4490067
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000185507-IRF7/tissue/kidney#imid_4490060
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA052757; green = IRF7, blue = nucleus, red = microtubules.
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA052757; green = IRF7, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for IRF7 IHC & IF
🧪Run bone marrow first and expect staining in hematopoietic cells (HPA: High in bone marrow hematopoietic cells). HPA detects IRF7 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls, and expect cells without detectable signal on the positive slide to remain at background without assigning them a negative cell type (HPA: no negative rows; standard IHC practice).
Positive control tissue: Adipose tissue (Adipocytes, HPA High)
Negative control tissue: None in HPA: IRF7 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show IRF7 in HEK293, PC-3, U2OS, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a control using nonimmune rabbit IgG matched to the primary antibody’s clonality when known, and a matched IRF7-knockout sample where available (A00115-3 tissue-IHC caption: rabbit primary; standard IHC practice). Quench endogenous peroxidase and check background in blood-rich bone marrow areas before interpreting DAB staining (standard IHC practice).
⚠️Feasibility: Paraffin-section IHC is demonstrated in human spleen with heat-mediated EDTA retrieval at pH 8.0; the selected A00115-3 caption does not report a fixative, and no IRF7-specific fixation window or fixation effect is supplied (A00115-3 tissue-IHC caption). HPA provides ICC-IF images in HEK293, PC-3 and U2OS, but the supplied evidence does not establish whether frozen sections or IF are easier than paraffin IHC (HPA subcellular). In bone marrow, endogenous peroxidase in blood-rich areas can complicate chromogenic interpretation (standard IHC practice).
HPA tissue IHC evidence for IRF7
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — 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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: IRF7 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced IRF7 IHC Tips
Troubleshoot IRF7 staining in paraffin sections, with one note on translating the assay to immunofluorescence.
Which retrieval conditions should I try when IRF7 staining is weak?
Start with heat-mediated retrieval in EDTA, pH 8.0, as used for the catalog antibody in a paraffin-embedded human spleen section (datasheet A00115-3). Keep heating and cooling conditions consistent across sections, then compare staining with a matched section processed without retrieval to assess whether retrieval improves the signal. The documented workflow used 2 μg/ml primary antibody overnight at 4°C, so match those conditions before changing several variables at once (datasheet A00115-3). If staining remains weak, trial an alternative retrieval buffer on adjacent sections as a fallback, recording both signal and tissue preservation.
How should I troubleshoot suspected fixation-related loss of IRF7 staining?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative, and its staining cannot establish how IRF7 responds to fixation (datasheet A00115-3). Record the specimen’s actual fixative and fixation duration, then compare similarly handled sections before attributing a weak result to the antibody. For a controlled check, process matched material with different fixation durations under the same EDTA, pH 8.0 retrieval and primary-antibody conditions (datasheet A00115-3). Review morphology alongside staining, since damaged or poorly preserved areas make intensity difficult to interpret. Treat any resulting fixation preference as an observation from that comparison, not an established property of IRF7.
Should IRF7 staining be nuclear or cytoplasmic in tissue sections?
Assess nuclear and cytoplasmic staining separately: IRF7 is reported in both compartments, while its phosphorylated active form accumulates selectively in the nucleus (UniProt Q92985 subcellular location). The tissue atlas describes nuclear expression in most tissues and distinct expression in lymphatic organs, with Approved reliability and medium consistency with RNA data (HPA tissue IHC). Compare each compartment with the counterstained cell boundaries and with a negative-control section rather than treating all brown signal as equivalent. A nuclear shift can support activation, but total-IRF7 chromogenic staining alone cannot demonstrate phosphorylation or transcriptional activity (UniProt Q92985 function and modified residues).
Could IRF7 isoforms or modifications explain inconsistent staining?
IRF7 has four annotated isoforms, A through D, so check the catalog antibody’s stated immunogen or epitope before assuming it detects every form (UniProt Q92985 isoforms). The record also lists acetylation and phosphorylation, including phosphoserines at residues 471, 472, 475, and 477 (UniProt Q92985 modified residues). No epitope map is supplied here, so a modification-dependent change in binding is a possibility to test, not an explanation established by these data. Compare staining with an independently validated antibody targeting a different documented epitope if available, while keeping retrieval, detection, and section processing matched.
How can I adapt this IRF7 IHC assessment to multiplex immunofluorescence?
Treat IF/ICC as a separate validation: the supplied catalog evidence documents chromogenic staining of a paraffin-embedded human spleen section, with EDTA, pH 8.0 retrieval (datasheet A00115-3). Pair IRF7 with a validated marker for the cell population under study, and use a nuclear counterstain to score nucleoplasmic versus cytosolic signal (HPA subcellular; UniProt Q92985 subcellular location). Choose spectrally separated fluorophores after checking unstained tissue for autofluorescence, especially in the channels used for weak signals. Because IRF7 has no transmembrane segment and occurs in intracellular compartments, use a compatible permeabilisation step, then titrate it while checking morphology and background (UniProt Q92985 topology and subcellular location).
What should I check when IRF7 DAB staining is diffuse or widespread?
First inspect a no-primary control and compare it with the IRF7 section to identify signal from detection reagents or endogenous peroxidase. Include a peroxidase-blocking step before HRP detection, and keep DAB development consistent across comparison sections; the documented assay used an HRP-based system with DAB (datasheet A00115-3). If background persists, titrate the primary around the documented 2 μg/ml starting condition and check whether blocking or wash conditions need adjustment (datasheet A00115-3). Judge apparent positives against cell morphology and compartment: supported IRF7 locations include the nucleoplasm and cytosol, so diffuse extracellular precipitate needs separate scrutiny (HPA subcellular).
How should I quantify nuclear and cytoplasmic IRF7 staining? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and tissue region before scoring, then report nuclear and cytoplasmic IRF7 separately because both locations are supported (HPA subcellular; UniProt Q92985 subcellular location). For chromogenic sections, record the percentage of positive cells and an intensity-based H-score, or report positive-cell density per mm² when cell abundance varies. Normalise counts to the number of eligible cells or the measured tissue area, and apply the same threshold, counterstain settings, and exclusion rules to every section. Stratify by cell type where possible; the tissue atlas reports distinct expression in lymphatic organs and nuclear expression across most tissues (HPA tissue IHC).
How can I distinguish credible IRF7 staining from artefact?
Look for reproducible intracellular signal in morphologically intact cells, then compare its compartment with the reported nucleoplasmic and cytosolic locations (HPA subcellular). Interpret nuclear enrichment cautiously: phosphorylated active IRF7 accumulates in nuclei, but a total-protein IHC stain does not identify the phosphorylated species by itself (UniProt Q92985 subcellular location and function). Compare the suspected positive population with tissue context; IRF7 is expressed predominantly in spleen, thymus, and peripheral blood leukocytes (UniProt Q92985 tissue specificity). Discount staining confined to section edges, necrotic regions, extracellular deposits, or the no-primary control, and investigate residual endogenous peroxidase when DAB appears independently of primary antibody.
Boster reagents
Best IRF7 / Interferon regulatory factor 7 IHC Antibodies
Both anti-IRF7 antibodies have real IHC images from human paraffin sections: spleen and pancreas (IHC captions). M00115 also lists IF/ICC and mouse/rat reactivity (catalog: M00115).
Real IHC data
Anti-IRF7 Antibody ®
Cat # A00115-3
Real IHC data
Anti-IRF7 Rabbit Monoclonal Antibody
Cat # M00115
A00115-3 is listed for human IHC and shows staining in a paraffin-embedded human spleen section (catalog: A00115-3 applications and reactivity; A00115-3 IHC caption). M00115 is listed for human, mouse and rat IHC/IF/ICC and shows IHC staining in a paraffin-embedded human pancreas section (catalog: M00115 applications and reactivity; M00115 IHC caption).
Which to pick: Choose A00115-3 for human paraffin-section IHC when its documented EDTA pH 8 retrieval and DAB workflow suits the experiment (A00115-3 IHC caption). Choose M00115 for IF/ICC or cross-species experiments because it is a rabbit monoclonal listed for IF/ICC and human, mouse and rat reactivity (catalog: M00115 host, clone, applications and reactivity). Both IHC captions document paraffin sections; neither reports the fixative (A00115-3 and M00115 IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q92985 (IRF7_HUMAN, Interferon regulatory factor 7).
- Human Protein Atlas. IRF7 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. IRF7 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. IRF7 antibody validation summary (2 antibodies).
- Profiling of gallbladder carcinoma reveals distinct miRNA profiles and activation of STAT1 by the tumor suppressive miRNA-145-5p. Scientific reports 2019 — PMC6423323.
- The cGAS-STING-interferon regulatory factor 7 pathway regulates neuroinflammation in Parkinson's disease. Neural regeneration research 2025 — PMC11759022.
- Transcription Factor IRF7 is Involved in Psoriasis Development and Response to Guselkumab Treatment. Journal of inflammation research 2024 — PMC10876010.
- Fibroblast IRF7-mediated chondrocyte apoptosis affects the progression of collapse in steroid-induced osteonecrosis of the femoral head. Journal of orthopaedic surgery and research 2025 — PMC11921700.
- PubMed PMID:9315633 — UniProt-cited evidence.
- PubMed PMID:9786932 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for IRF7 (Interferon regulatory factor 7). Expected localisation Nuclear staining in most tissues (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A00115-3). Validated IHC antibody: A00115-3 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human spleen tissue; fixative not specified (datasheet A00115-3); 2. Fixation: Image fixative and duration unreported (datasheet A00115-3); 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 A00115-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A00115-3); 8. Primary antibody: Rabbit anti-IRF7, 2-5 μg/ml (datasheet A00115-3); 9. Primary incubation: Overnight at 4 °C (datasheet A00115-3). Watch for: Fixation: Keep paraffin-section fixation consistent across samples. (standard IHC practice; not target-specific); Caveat: Activation can shift IRF7 from cytoplasm to nucleus (UniProt); Isoform / epitope: 4 isoforms (A–D); check epitope coverage before isoform scoring (UniProt); Regulation: Viral/TLR signaling activates IRF7 (UniProt). Evidence: UniProt Q92985, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A00115-3, PMC6423323, PMC11759022. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/IRF7/immunohistochemistry-ihc-guide.