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IFIT1 / Antiviral innate immune response effector IFIT1 · IHC design guide
Design Immunohistochemistry for IFIT1
Plan paraffin-section IFIT1 IHC around the cytoplasmic staining reported in most tissues (HPA tissue IHC). Use consistent fixation and appropriate controls when comparing intensity, since staining and RNA show low consistency (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
IFIT1 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 | Cytoplasm (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in most tissues (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 8.0 HIER, heat-mediated (datasheet A02652) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Adipose tissue+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) | |
| Caveat | Staining and RNA show low consistency (HPA tissue IHC) | |
| Regulation | Interferon induced (UniProt) | |
| Isoform / epitope | 2 isoforms; verify antibody epitope coverage (UniProt) |
Section 1
Recommended IFIT1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A02652) is accompanied by four published IFIT1 IHC protocols (PMC8749771; PMC9664554; PMC13529458; PMC13202916).
| Sample | Paraffin-embedded Human brain tissue; fixative not specified (datasheet A02652) |
| Fixation | Image fixative and duration unreported (datasheet A02652); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Tris-EDTA pH 8.0 (datasheet A02652); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-IFIT1, 1:100 - 1:300 (datasheet A02652) |
| Primary incubation | Overnight at 4 °C (standard) |
| Detection | HRP-polymer secondary, DAB chromogen 5–10 min (standard) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | IFIT1-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated Tris-EDTA retrieval at pH 8.0 for the catalog antibody (datasheet A02652). Use each paper’s stated retrieval conditions when reproducing its protocol.
Section 2
What Is the Expected IFIT1 Staining Pattern?
IFIT1 is cytoplasmic, with ICC-IF showing a cytosolic pattern (UniProt P09914; HPA: cytosol, enhanced). In paraffin-section IHC, expect staining in the cell populations HPA reports as positive, including lung macrophages, liver hepatocytes and heart cardiomyocytes (HPA: medium in each). HPA rates its tissue pattern Supported, but reports low agreement with RNA expression and says external verification is pending (HPA: tissue IHC reliability).
| Cytoplasmic stain in lung macrophages, liver hepatocytes or heart cardiomyocytes, with identifiable cell boundaries and a clear counterstain. | This matches the reported compartment and cell populations; HPA calls staining medium in each (UniProt P09914: cytoplasm; HPA: tissue IHC). Compare cells within the same section rather than treating all tissue as uniformly positive. |
| Predominantly nuclear, membranous or extracellular stain, without convincing cytoplasmic signal. | That distribution conflicts with the reported cytoplasmic location (UniProt P09914; HPA: cytosol). Check morphology and controls before calling it IFIT1; misplaced signal can reflect nonspecific staining or a slide artefact. |
| Strong stain in an unexpected cell population while the expected population is unstained. | Assess that exact tissue and cell type against HPA, which also reports low or undetected staining in some populations (HPA: tissue IHC). Cross-reactivity or endogenous detection activity is possible; appearance alone cannot distinguish them. |
| Diffuse brown haze over cells, stroma or blank areas, with little separation between compartments. | The haze cannot establish cytoplasmic IFIT1 localisation (UniProt P09914: cytoplasm). General IHC causes include excessive background from detection reagents, incomplete blocking or insufficient washing; inspect a no-primary control. |
| No discernible stain in a section containing a reported medium-positive cell population. | HPA reports, for example, medium staining in kidney glomerular cells and pancreatic endocrine cells (HPA: tissue IHC). A blank result calls for assay checks, but HPA's Supported rating and pending external verification limit claims about any individual specimen. |
💡Expected IFIT1 appearanceCall an IHC result consistent with IFIT1 when identifiable, reported positive cells show primarily cytoplasmic stain near the HPA medium examples (UniProt P09914: cytoplasm; HPA: tissue IHC); isolated nuclear, extracellular or slide-wide brown signal is suspect.
| Compartment and topology | IFIT1 is cytoplasmic and has no annotated transmembrane segment (UniProt P09914). Expect an intracellular pattern; membrane outlining alone does not match that record. HPA independently places ICC-IF signal in the cytosol (HPA: subcellular). |
| Choice of tissue and cell population | HPA reports medium staining in lung macrophages and liver hepatocytes, but no detection in adipocytes or bone-marrow hematopoietic cells (HPA: tissue IHC). Use the annotated cell population, not the tissue name alone, when judging a section. |
| Strength of evidence | HPA rates the tissue pattern Supported while noting low consistency with RNA and pending external verification (HPA: tissue IHC reliability). HPA lists IHC as Supported for 3 antibodies: HPA055380, CAB045980 and CAB080338 (HPA: antibody validation). |
| Isoforms and processing | UniProt lists 2 isoforms and no signal peptide or propeptide (UniProt P09914). The record does not establish which isoforms an individual antibody detects; do not infer antibody coverage or extracellular release from these annotations. |
| Detection activity | In chromogenic IHC, endogenous enzyme activity or pigment can mimic brown product (general IHC practice). A no-primary control helps assess detection-derived staining; this is a workflow consideration, not an IFIT1-specific effect. |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected positive cells are blank. | The cause is unresolved from a single section; HPA reports medium staining in lung macrophages, among other cells, but flags limited tissue-pattern certainty (HPA: tissue IHC). | Confirm that the annotated cell type is present, then review the catalog antibody's IHC-P instructions and run a documented positive section alongside the sample. Do not infer IFIT1 absence from the blank slide alone. |
| Brown signal is mainly nuclear or outlines membranes. | The pattern disagrees with cytoplasmic IFIT1 and HPA's cytosolic ICC-IF result (UniProt P09914; HPA: subcellular). It may reflect nonspecific staining or misread morphology. | Use the counterstain to identify nuclei and cell borders, inspect a no-primary control, and score only signal whose compartment can be assigned confidently. |
| Unexpected cell types stain strongly. | HPA's observations vary by cell population, including no detection in adipocytes and bone-marrow hematopoietic cells (HPA: tissue IHC). Cross-reactivity or endogenous detection activity may explain discordant stain. | Compare the exact population with HPA's tissue entry and the no-primary control. If the unexpected pattern persists, seek independent antibody or orthogonal evidence before assigning IFIT1. |
| The whole section has diffuse brown background. | Excess detection signal, endogenous activity or inadequate washing can obscure cell-specific staining (general chromogenic IHC practice). Haze by itself does not establish the UniProt cytoplasmic pattern (UniProt P09914). | Review blocking and wash steps, inspect a no-primary control, and judge the sample only when cytoplasmic signal can be separated from surrounding background. |
| A reported negative population shows a few stained cells. | The HPA label applies to its named population and observations, not necessarily every neighboring cell or specimen (HPA: tissue IHC). Mixed cells, pigment or nonspecific signal may account for isolated positives. | Identify the stained cells morphologically, compare an adjacent section if available, and avoid calling a tissue-wide positive result from scattered unassigned cells. |
| IF/ICC shows a different compartment from the IHC section. | HPA reports cytosol as the enhanced ICC-IF location, with images from A-431, HeLa and U2OS (HPA: subcellular). Different specimens and detection methods can complicate direct comparison (general practice). | For this IHC interpretation, check compartment assignment and controls first; use the separate IF/ICC guide for its method. Treat a reproducible compartment conflict as unresolved until independently checked. |
Experiment evidence
IHC & IF images showing IFIT1 staining
A02652 · IHCImmunohistochemical analysis of paraffin-embedded Human brain. Antibody was diluted at 1:100(4° overnight). High-pressure and temperature Tr
A02652-1 · IHCImmunohistochemistry of IFIT1 in human small intestine tissue with IFIT1 antibody at 5 μg/mL.
A02652-1 · IFImmunofluorescence of IFIT1 in human small intestine tissue with IFIT1 antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000185745-IFIT1/tissue/cerebral+cortex#imid_14435296
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000185745-IFIT1/tissue/colon#imid_14435222
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000185745-IFIT1/tissue/liver#imid_14435223
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000185745-IFIT1/tissue/kidney#imid_14435216
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA053890; green = IFIT1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA053890; green = IFIT1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for IFIT1 IHC & IF
🧪Run duodenum first and look for staining in glandular cells (HPA: Medium in duodenal glandular cells). Use cervix as the negative tissue, focusing on glandular cells (HPA: Not detected in cervical glandular cells); on the duodenum slide, cells outside the stained glands should show only background-level signal, without assuming they are biologically IFIT1-negative.
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show IFIT1 in A-431, HeLa, U2OS, with annotated localisation: Cytosol (enhanced) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and host-species- and isotype-matched controls, and assess target specificity with an IFIT1 knockout specimen or peptide preabsorption (selected SKU A02652 tissue-IHC caption: peptide-preabsorbed negative control). For chromogenic IHC, quench endogenous peroxidase and check endogenous biotin if using avidin–biotin detection; for IF, check tissue autofluorescence.
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the fixative in the selected SKU A02652 paraffin-section caption is unreported (selected SKU A02652 tissue-IHC caption). That caption used high-pressure, heated Tris-EDTA retrieval at pH 8.0, but does not establish that IFIT1 staining depends on that retrieval method (selected SKU A02652 tissue-IHC caption). Whether frozen sections or IF are easier is unreported; inspect the duodenal lumen for nonspecific signal when scoring glandular cells (HPA: Medium in duodenal glandular cells).
HPA tissue IHC evidence for IFIT1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — Low consistency between antibody staining and RNA expression data. Pending external verification.). 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | Medium | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | Medium | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | Medium | Protein (IHC) | HPA → |
| Kidney | Cells in glomeruli | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced IFIT1 IHC Tips
Troubleshoot IFIT1 staining in paraffin sections by checking retrieval, cytoplasmic localisation, controls and cell-specific scoring (UniProt P09914; HPA tissue IHC).
Which retrieval conditions should I start with for IFIT1 in paraffin sections?
Start with heat-mediated Tris-EDTA at pH 8.0 for IFIT1 paraffin-section IHC (datasheet A02652). The selected human brain image used high pressure and temperature with that buffer, but its caption does not report a heating time or fixative (datasheet A02652). Keep heating, cooling and antibody incubation consistent across sections while optimizing the retrieval duration according to the equipment and tissue condition (standard IHC practice). If staining is weak, compare a shorter and longer heating interval on adjacent sections, watching for tissue damage or increased background (standard IHC practice). Include a section without primary antibody to distinguish retrieval-related background from IFIT1 staining (standard IHC practice).
How should I handle fixation when IFIT1 staining varies between paraffin blocks?
Target-specific IFIT1 sensitivity to fixation is unknown from the supplied evidence; the selected paraffin-section caption does not state a fixative (datasheet A02652). Record each block’s fixative, fixation duration and processing history before comparing staining intensities (standard IHC practice). Use similarly processed sections, the same pH 8.0 retrieval and matched antibody incubation when testing whether preparation accounts for variation (datasheet A02652; standard IHC practice). Compare preserved cellular morphology and cytoplasmic staining together, since damaged sections can make cell-level interpretation unreliable (UniProt P09914 subcellular; standard IHC practice). Do not assign a target-specific fixation effect without a direct comparison using controlled specimens (standard IHC practice).
What staining pattern is expected, and how should I investigate nuclear signal?
Assess IFIT1 primarily as cytoplasmic staining: UniProt places it in the cytoplasm, and HPA reports cytosolic localisation (UniProt P09914 subcellular; HPA subcellular). HPA also describes cytoplasmic expression across most tissues in its tissue IHC profile (HPA tissue IHC). If nuclei dominate, review the haematoxylin counterstain, focal plane and deposit distribution, then compare a section without primary antibody (standard IHC practice). Score cytoplasm separately from nuclei rather than treating all chromogen as equivalent IFIT1 signal (UniProt P09914 subcellular; standard IHC practice). Check whether apparent nuclear deposits cluster at section edges or damaged areas before interpreting them biologically (standard IHC practice).
Can this stain distinguish IFIT1 isoforms or reveal an inaccessible epitope?
IFIT1 has 2 listed isoforms, but the supplied antibody caption does not identify its epitope or establish isoform-specific recognition (UniProt P09914 isoforms; datasheet A02652). Its annotated chain spans residues 1–478, with no signal peptide, propeptide or transmembrane segment reported (UniProt P09914 processing and topology). Therefore, do not assign an isoform from chromogenic intensity or compartment alone (UniProt P09914 isoforms; standard IHC interpretation). If expected cytoplasmic staining is absent, check the antibody’s documented immunogen or epitope information before choosing additional controls (UniProt P09914 subcellular; standard IHC practice). Compare retrieval conditions on matched sections when assessing possible epitope masking, while monitoring morphology and background (standard IHC practice).
How can IF help check the cellular source of an IHC signal?
Use IF/ICC as a separate corroborating experiment; the selected A02652 image documents paraffin-section IHC and supplies no IF/ICC protocol (datasheet A02652). Multiplex IFIT1 with a validated macrophage marker when examining lung, where HPA reports medium staining in macrophages (HPA tissue IHC; standard IF practice). Choose fluorophores after checking the specimen’s autofluorescence in each imaging channel, and include single-label and no-primary controls for signal separation (standard IF practice). IFIT1 is cytosolic and has no annotated transmembrane segment, so permeabilise fixed cells or sections sufficiently to expose intracellular epitopes, then optimize conditions for the chosen antibodies (HPA subcellular; UniProt P09914 topology; standard IF practice). Compare the resulting cell-level pattern with IHC without assuming identical detection sensitivity (standard IHC/IF practice).
How do I distinguish diffuse IFIT1 staining from nonspecific chromogen?
First inspect a section processed without primary antibody; persistent deposits point to the detection workflow or tissue background rather than primary-antibody binding (standard IHC practice). For peroxidase-based chromogenic IHC, apply a peroxidase block and assess whether endogenous activity remains before interpreting DAB deposits (standard IHC practice). The selected image includes a negative control made by preabsorbing A02652 with immunogen peptide, providing a product-specific comparison for that image (datasheet A02652). Compare diffuse staining with intact cytoplasm, since IFIT1 is cytoplasmic and HPA reports cytosolic localisation (UniProt P09914 subcellular; HPA subcellular). Optimize blocking, washing and antibody concentration on adjacent sections if background obscures cells (standard IHC practice).
What is a defensible way to quantify IFIT1 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue region and cell population before scoring, then record the percentage of cells with cytoplasmic staining and its intensity (UniProt P09914 subcellular; standard IHC practice). An H-score combines percentage at each intensity category into a 0–300 summary when a consistent scoring scale is used (standard IHC practice). Alternatively, report positive-cell density per mm² and normalize it to the measured viable tissue area or the number of relevant cells (standard IHC practice). Keep retrieval, antibody incubation, detection development and imaging conditions matched across compared sections (standard IHC practice). Report cell populations separately because HPA’s tissue observations vary by cell type (HPA tissue IHC).
When is an IFIT1-positive cell convincing rather than a staining artefact?
A convincing cell shows interpretable cytoplasmic staining within preserved morphology, consistent with IFIT1’s reported cytoplasmic and cytosolic localisation (UniProt P09914 subcellular; HPA subcellular; standard IHC practice). Cell identity matters: HPA reports medium signal in lung macrophages and liver hepatocytes, but its tissue IHC reliability is Supported with low consistency against RNA data and pending external verification (HPA tissue IHC). Treat isolated nuclear deposits, section-edge enhancement and necrotic areas cautiously, and compare them with intact internal regions (UniProt P09914 subcellular; standard IHC practice). Exclude residual endogenous peroxidase activity with an appropriate detection control before calling DAB deposits positive (standard IHC practice). Interpret staining alongside matched controls and cell-specific morphology rather than intensity alone (standard IHC practice).
Boster reagents
Best IFIT1 / Antiviral innate immune response effector IFIT1 IHC Antibodies
Two anti-IFIT1 antibodies have IHC images: A02652 in human brain paraffin sections and A02652-1 in human small intestine; A02652-1 also has an IF image in human small intestine (catalog image captions).
Real IHC data
Anti-IFIT1 Antibody
Cat # A02652
Real IHC data
Anti-IFIT1 Antibody
Cat # A02652-1
A02652 has an IHC image from human brain paraffin sections at 1:100 and lists IF and ICC applications (A02652 image caption; catalog applications). A02652-1 has IHC and IF images from human small intestine at 5 μg/mL and 20 μg/mL, respectively (A02652-1 image captions).
Which to pick: For paraffin-section IHC, choose A02652 when its documented human brain example and Tris-EDTA pH 8.0 retrieval fit the experiment; its caption does not report the fixative (A02652 IHC image caption). For IF/ICC, A02652 lists both applications, while A02652-1 has a human small-intestine IF image but does not list ICC (catalog applications; A02652-1 IF image caption). Both list human, mouse and rat reactivity, but the supplied IHC images document human tissue only; A02652 is described as polyclonal, and A02652-1’s clonality is unreported (catalog reactivity; IHC image captions; A02652 dilution data).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P09914 (IFIT1_HUMAN, Antiviral innate immune response effector IFIT1).
- Human Protein Atlas. IFIT1 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. IFIT1 subcellular location (ICC-IF): Localized to the cytosol..
- Human Protein Atlas. IFIT1 antibody validation summary (4 antibodies).
- Bioinformation Analysis Reveals IFIT1 as Potential Biomarkers in Central Nervous System Tuberculosis. Infection and drug resistance 2022 — PMC8749771.
- Fusobacterium nucleatum stimulates cell proliferation and promotes PD-L1 expression via IFIT1-related signal in colorectal cancer. Neoplasia (New York, N.Y.) 2023 — PMC9664554.
- Myeloma-derived exosomal circ_0002724 promotes osteoclastogenesis through a miR-4753-3p/IFIT1 and RANK axis in myeloma bone disease. Frontiers in oncology 2026 — PMC13529458.
- Arecoline-induced EV-mediated ZNF582 hypermethylation drives IFIT1-PD-L1 immune evasion in oral squamous cell carcinoma. Clinical epigenetics 2026 — PMC13202916.
- PubMed PMID:3753936 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15164054 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for IFIT1 (Antiviral innate immune response effector IFIT1). Expected localisation Cytoplasm (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 8.0 HIER, heat-mediated (datasheet A02652). Validated IHC antibody: A02652 at 1:100 - 1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded Human brain tissue; fixative not specified (datasheet A02652); 2. Fixation: Image fixative and duration unreported (datasheet A02652); 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: Tris-EDTA pH 8.0 (datasheet A02652); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-IFIT1, 1:100 - 1:300 (datasheet A02652); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining and RNA show low consistency (HPA tissue IHC); Isoform / epitope: 2 isoforms; verify antibody epitope coverage (UniProt); Regulation: Interferon induced (UniProt). Evidence: UniProt P09914, HPA tissue IHC · Supported, HPA ICC-IF · cytosol., Datasheet A02652, PMC8749771, PMC9664554. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/IFIT1/immunohistochemistry-ihc-guide.