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FER / Tyrosine-protein kinase Fer · IHC design guide
Design Immunohistochemistry for FER
Plan FER staining in paraffin sections using its observed cytoplasmic tissue pattern (HPA tissue IHC). The guide covers fixation consistency, antibody dilution, controls and interpretation, including the reported mismatch between staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
FER 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 observed in tissue (HPA tissue IHC) | |
| Staining pattern | General cytoplasmic staining across tissue cell types (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| 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 fixation consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Staining has low consistency with RNA expression (HPA tissue IHC) | |
| Regulation | No expression regulator specified (UniProt) | |
| Isoform / epitope | 3 isoforms; epitope coverage is unknown (UniProt) |
Section 1
Recommended FER IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet) with three published FER IHC protocols (PMC3573111; PMC5351348; PMC3898493).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet PA1882); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear antigen) |
| 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-FER, 0.5-1μg/ml (datasheet PA1882) |
| 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 | FER-positive staining in adipocytes of adipose tissue (HPA tissue IHC: Medium). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0, 95–98 °C, 20 min (page antigen retrieval); compare published citrate pH 6.0 (PMC3573111; PMC3898493) or EDTA pH 8.0 (PMC5351348).
Section 2
What Is the Expected FER Staining Pattern?
FER is expected mainly in the cytoplasm, with possible staining at the cell cortex or cell junctions (UniProt P16591 localization; HPA: general cytoplasmic expression). HPA reports medium staining in several cell populations, including bone marrow hematopoietic cells and bronchial respiratory epithelial cells (HPA: tissue IHC). Treat these as reference patterns rather than definitive controls: HPA rates the tissue IHC profile Approved but reports low consistency with RNA expression (HPA: reliability). FER has no transmembrane segment (UniProt P16591 topology).
| Cytoplasmic staining in bone marrow hematopoietic cells or bronchial respiratory epithelial cells. | This fits HPA's medium staining in those populations and its general cytoplasmic profile (HPA: tissue IHC). Compare the intended cell population and compartment on the same slide; stain color alone cannot establish specificity (general IHC practice). |
| Predominantly extracellular staining, with little signal inside cells. | This conflicts with the reported cytoplasmic pattern and FER's lack of a signal peptide or transmembrane segment (HPA: tissue IHC; UniProt P16591 processing and topology). Check section edges, deposits and the detection control before interpreting it as FER (general IHC practice). |
| Strong staining in an unexpected cell population while the reference population is unstained. | Consider antibody cross-reactivity or endogenous detection activity (general IHC practice). HPA reports broad tissue staining and low RNA specificity, so an unlisted population is not automatically false positive (HPA: tissue IHC); assess cell identity and controls together. |
| A uniform haze covers cells and surrounding tissue. | Diffuse background obscures whether staining is cellular and cytoplasmic (general IHC practice). Review the no-primary control, blocking, antibody concentration and washes; none of these observations alone identifies a FER-specific cause (general IHC practice). |
| No staining in a reference tissue expected to show medium signal. | First confirm that the relevant cells are present: HPA reports medium signal in adipocytes, bone marrow hematopoietic cells and bronchial respiratory epithelial cells (HPA: tissue IHC). Then review the assay controls and retrieval conditions (general IHC practice); HPA's low RNA concordance limits any single tissue's value as a definitive control (HPA: reliability). |
💡Expected FER appearanceA convincing positive is chiefly cytoplasmic, with approximately medium staining in an HPA-listed cell population; extracellular deposits or uniform tissue haze warrant a control check (HPA: tissue IHC; general IHC practice).
| Which compartment should guide IHC interpretation? | HPA describes general cytoplasmic tissue staining (HPA: tissue IHC). UniProt also lists cytoskeleton, cell cortex, junctions, membrane and nucleus (UniProt P16591 localization), so a limited noncytoplasmic component needs context; extracellular-only staining is harder to reconcile with the record (UniProt P16591 processing and topology). |
| How strong is the tissue reference? | The HPA tissue profile is Approved, yet its antibody staining has low consistency with RNA expression (HPA: reliability). Listed medium or low staining is useful for comparison, but neither an unexpected positive nor a missing signal in one section settles specificity (HPA: tissue IHC; general IHC practice). |
| Could the antibody distinguish FER isoforms? | UniProt lists three isoforms; isoform 1 occurs in normal colon and fibroblasts, whereas isoform 3 was not detected in those normal samples (UniProt P16591 tissue specificity). Antibody epitope and isoform coverage are unspecified here, so IHC staining cannot be assigned to one isoform from these data. |
| Do the listed modifications predict retrieval? | FER has reported phosphorylation sites, including Tyr402 and Ser434 (UniProt P16591 modified residues). The supplied sources do not map this antibody's epitope or report FER-specific retrieval or fixation sensitivity; choose and document retrieval using the assay protocol, then evaluate controls (general IHC practice). |
| What does antibody validation establish? | HPA lists HPA007641 and CAB022464 as IHC Approved; HPA007641 is ICC Supported (HPA: antibodies). These statuses support use of the reported patterns for comparison, while the tissue profile's low RNA concordance still warrants slide-level controls (HPA: reliability; general IHC practice). |
| What should IF/ICC show? | HPA reports supported cytosolic localization and lists images from A-431, U-251MG and U2OS (HPA: subcellular ICC-IF). Use that localization as the IF/ICC comparison; this IHC section supplies no IF/ICC protocol. |
| Situation | Likely cause | Next action |
|---|---|---|
| Reference cells appear negative. | The expected cell population may be absent, or the staining run may have failed (HPA: tissue IHC; general IHC practice). | Check tissue morphology and a run control, then review the recorded retrieval, primary antibody dilution and detection steps (general IHC practice). HPA's medium examples are reference patterns, not guaranteed positives in every section (HPA: reliability). |
| Only extracellular material or tissue edges stain. | The distribution conflicts with HPA's cytoplasmic pattern and FER's lack of a signal peptide or transmembrane segment (HPA: tissue IHC; UniProt P16591 processing and topology). | Inspect a no-primary control and the section for edge staining or deposits; repeat the stain if the control suggests detection background (general IHC practice). |
| Every cell has a weak, even haze. | Nonspecific reagent binding or incomplete washing can obscure cell boundaries (general IHC practice). | Compare the no-primary control, review blocking and washes, and adjust primary antibody concentration within the validated assay range (general IHC practice). Do not score haze as FER-positive cytoplasm. |
| An unexpected cell type stains more strongly than HPA-listed cells. | Cross-reactivity or endogenous detection activity is possible, but FER is widely expressed and HPA reports low tissue specificity (UniProt P16591 tissue specificity; HPA: tissue IHC). | Check morphology and detection controls, then compare an independently validated antibody if available (general IHC practice). Record the discrepancy without declaring the cell type negative solely because it is absent from HPA's list. |
| Staining is mainly nuclear or junctional. | UniProt lists nucleus and cell junction among FER locations, while HPA summarizes tissue IHC as generally cytoplasmic (UniProt P16591 localization; HPA: tissue IHC). | Document whether cytoplasmic staining accompanies it and compare controls and repeat sections (general IHC practice). Avoid assigning a nuclear-only or junction-only result to FER from location alone. |
| Two stained sections disagree in intensity. | Differences in cell composition or staining-run conditions can affect a comparison (general IHC practice); HPA also reports low consistency between antibody staining and RNA data (HPA: reliability). | Compare the same cell population, counterstain and run controls; review retrieval, dilution and detection records before scoring a biological difference (general IHC practice). |
Experiment evidence
IHC & IF images showing FER staining
PA1882 · IHCAnti-FER antibody, PA1882, IHC(P) IHC(P): Human Intestinal Cancer Tissue
PA1882 · IHCAnti-FER antibody, PA1882, IHC(P) IHC(P): Rat Intestine Tissue
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000151422-FER/tissue/cerebral+cortex#imid_6411544
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000151422-FER/tissue/colon#imid_6412118
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000151422-FER/tissue/liver#imid_6412119
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000151422-FER/tissue/kidney#imid_6412112
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA007641; green = FER, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA007641; green = FER, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for FER IHC & IF
🧪Run appendix first: its lymphoid tissue should show FER staining at a Medium level (HPA: appendix, lymphoid tissue, Medium). HPA detects FER in all 45 scored tissues, so there is no validated negative tissue; use no-primary and isotype controls, and treat any unstained cells on the positive slide as a local background reference rather than confirmed FER-negative cells (HPA: no negative tissue rows).
Positive control tissue: Adipose tissue (Adipocytes, HPA Medium)
Negative control tissue: None in HPA: FER 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 FER in A-431, U-251MG, U2OS, with annotated localisation: Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only section and a control immunoglobulin matched to the primary antibody’s host species, isotype, and clonality; compare them with a FER knockout specimen or, if the immunizing peptide is available, a peptide-blocked primary (standard IHC control practice). Block endogenous peroxidase and check for residual chromogen signal in appendix lymphoid tissue (HPA: appendix lymphoid tissue; standard chromogenic IHC practice).
⚠️Feasibility: No supplied matched source reports a FER-specific fixation window, fixation effect, or antigen-retrieval dependency; establish retrieval conditions empirically for the chosen paraffin-section workflow (supplied target/application evidence). The PA1882 human intestinal cancer IHC(P) caption does not report a fixative (selected SKU tissue-IHC caption: PA1882). The supplied evidence does not establish whether frozen sections or IF would be easier; in appendix, endogenous peroxidase can complicate chromogenic scoring if incompletely blocked (HPA: appendix lymphoid tissue; standard IHC practice).
HPA tissue IHC evidence for FER
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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 | Medium | Protein (IHC) | HPA → |
| Appendix | Lymphoid tissue | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Adipocytes | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: FER is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced FER IHC Tips
Troubleshoot FER staining in paraffin sections by checking retrieval, cellular localisation, controls and scoring before interpreting chromogenic signal.
How should I optimise retrieval when FER staining is weak in paraffin sections?
Begin FER paraffin-section IHC with Tris-EDTA at pH 9.0, heated to 95–98 °C for 20 min (page retrieval setting). Keep section thickness, cooling time and chromogenic development consistent while comparing runs, so a change in retrieval is interpretable (standard IHC practice). If signal remains weak, test a shorter or longer heating period on matched sections before trying another buffer, and include a section processed without primary antibody (standard IHC practice). Assess whether stronger retrieval improves cellular cytoplasmic signal without increasing diffuse tissue staining or damaging morphology (HPA: general cytoplasmic expression; standard IHC practice).
Could fixation explain weak or variable FER staining across paraffin specimens?
FER-specific sensitivity to fixative choice, fixation duration and delay to fixation is unknown from the supplied evidence (evidence payload: no target-specific fixation data). The PA1882 tissue-IHC caption identifies human intestinal cancer tissue and paraffin IHC, but does not state the fixative (PA1882 tissue-IHC caption). Record those processing variables for each specimen and compare sections processed in the same batch before attributing a signal difference to FER biology (standard IHC practice). If a processing difference is suspected, stain matched control sections together and review morphology and background alongside FER signal; tissue staining patterns alone cannot establish fixation sensitivity (standard IHC practice).
Which cellular compartments should count as plausible FER staining?
Use cytoplasmic staining as the primary pattern to assess in chromogenic tissue sections (HPA: general cytoplasmic expression; HPA subcellular: supported cytosol). FER can also occur at the cortex, cell junctions, projections and nucleus, with reported association with chromatin, microtubules and F-actin (UniProt P16591 localisation). Because FER has no transmembrane segment, a crisp membrane outline alone should prompt review of morphology and antibody controls before it is called FER (UniProt P16591 topology; standard IHC practice). Score cytoplasmic, junctional and nuclear staining separately rather than combining them into one intensity value, and compare each pattern with its no-primary control (standard IHC practice).
Can this stain distinguish FER isoforms or modified FER?
Do not assign an IHC-positive cell to a particular FER isoform without an epitope map and isoform-specific validation for the antibody (UniProt P16591: three isoforms; supplied antibody evidence: epitope unspecified). FER contains an F-BAR region at residues 1–259, an SH2 domain at 460–550 and a kinase domain at 563–816 (UniProt P16591 domains). Document which region the antibody recognises, if known, before interpreting staining across specimens with potentially different isoform expression (UniProt P16591 tissue specificity; standard IHC practice). Phosphorylation at residues including 402, 615 and 714 does not make a total-FER stain a phosphorylation readout (UniProt P16591 modified residues; standard IHC interpretation).
How can I check FER localisation with multiplex immunofluorescence?
Use the separate IF/ICC guide for fluorescent staining; the curated workflow here concerns paraffin-section chromogenic IHC (application specification). To examine endothelial contacts, pair FER with PECAM1 and assess whether their signals meet at cell junctions rather than relying on apparent colour overlap alone (UniProt P16591 localisation; standard IF practice). Select a far-red fluorophore for a weak FER channel when tissue autofluorescence is prominent, and compare it with unstained and single-stain controls (standard IF practice). Because FER lacks a transmembrane segment and is supported in the cytosol, include a controlled mild permeabilisation step for intracellular epitope access while preserving junctional structure (UniProt P16591 topology; HPA subcellular: supported cytosol; standard IF practice).
What should I check when FER DAB signal appears diffuse?
First compare the stained section with a no-primary control to separate antibody-associated colour from tissue pigment or detection-system background (standard IHC practice). For a peroxidase and DAB workflow, block endogenous peroxidase before primary-antibody incubation; this is a general chromogenic IHC step, not FER-specific evidence (standard IHC practice). If background persists, check blocking, washing, primary-antibody concentration and DAB development on matched sections, changing one condition at a time (standard IHC practice). Review whether diffuse colour follows damaged edges, folds or necrotic areas instead of intact cells with a plausible cytoplasmic pattern (HPA: general cytoplasmic expression; standard IHC practice).
How should I quantify FER staining without mixing cell populations? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and tissue region before scoring, then exclude folds, necrosis and section edges by the same rule across specimens (standard IHC practice). For a defined population, record the percentage of positive cells and intensity categories from 0–3; their weighted sum gives an H-score from 0–300 (standard IHC scoring practice). Report cytoplasmic and nuclear scores separately because cytosol is supported while nuclear localisation is also reported (HPA subcellular: supported cytosol; UniProt P16591 localisation). Normalise positive-cell counts to all evaluable cells of that population, or report positive-cell density per mm² of evaluable tissue with the analysed area stated (standard IHC practice).
How can I distinguish convincing FER staining from artefact?
A credible result shows reproducible staining in intact cells with a plausible cytoplasmic pattern and a clean no-primary control (HPA: general cytoplasmic expression; standard IHC practice). Assess junctional or nuclear signal separately: both are biologically plausible for FER, but either pattern still needs appropriate antibody and morphology controls (UniProt P16591 localisation; standard IHC practice). Treat colour confined to section edges, folds or necrotic tissue as suspect, and check whether it persists when the primary antibody is omitted (standard IHC practice). Endogenous peroxidase can also create DAB colour, so verify the peroxidase block before interpreting a surprising cell population or compartment as FER-positive (standard IHC practice).
Boster reagents
Best FER / Tyrosine-protein kinase Fer IHC Antibodies
PA1882 has IHC images of human intestinal cancer tissue and rat intestine tissue in paraffin sections; no IF image is supplied (PA1882 IHC(P) captions; catalog IF images).
Real IHC data
Anti-Tyrosine-protein kinase Fer FER Antibody ®
Cat # PA1882
PA1882 is listed for IHC in human and rat samples (catalog applications and reactivity). Its IHC(P) images show human intestinal cancer tissue and rat intestine tissue (PA1882 IHC(P) captions).
Which to pick: Choose PA1882 for tissue IHC on paraffin sections, with a listed concentration of 0.5–1 μg/ml (PA1882 IHC(P) captions; datasheet). No SKU in this payload is listed for IF/ICC or has an IF image, so there is no supported IF/ICC pick (catalog applications and IF images). PA1882 is the documented human–rat IHC option; its clone and the tissue fixative are unreported (catalog reactivity and clone field; PA1882 IHC(P) captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P16591 (FER_HUMAN, Tyrosine-protein kinase Fer).
- Human Protein Atlas. FER tissue IHC expression (reliability: Approved).
- Human Protein Atlas. FER subcellular location (ICC-IF): Localized to the cytosol..
- Human Protein Atlas. FER antibody validation summary (2 antibodies).
- High expression of FER tyrosine kinase predicts poor prognosis in clear cell renal cell carcinoma. Oncology letters 2013 — PMC3573111.
- Downregulation of feline sarcoma-related protein inhibits cell migration, invasion and epithelial-mesenchymal transition via the ERK/AP-1 pathway in bladder urothelial cell carcinoma. Oncology letters 2017 — PMC5351348.
- FER kinase promotes breast cancer metastasis by regulating α6- and β1-integrin-dependent cell adhesion and anoikis resistance. Oncogene 2013 — PMC3898493.
- FER Regulated by miR-206 Promotes Hepatocellular Carcinoma Progression via NF-κB Signaling. Frontiers in oncology 2021 — PMC8289706.
- PubMed PMID:2725517 — UniProt-cited evidence.
- PubMed PMID:22223638 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for FER (Tyrosine-protein kinase Fer). Expected localisation Cytoplasmic staining observed in tissue (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: PA1882 at 0.5-1μg/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 workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet PA1882); 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-induced epitope retrieval in Tris-EDTA buffer, pH 9.0 , 20 min at 95–98 °C…; 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-FER, 0.5-1μg/ml (datasheet PA1882); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining has low consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 3 isoforms; epitope coverage is unknown (UniProt); Regulation: No expression regulator specified (UniProt). Evidence: UniProt P16591, HPA tissue IHC · Approved, HPA ICC-IF · cytosol., Datasheet PA1882, PMC3573111, PMC5351348. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/FER/immunohistochemistry-ihc-guide.