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GKN1 / Gastrokine-1 · IHC design guide
Design Immunohistochemistry for GKN1
Plan GKN1 staining in paraffin sections around the expected cytoplasmic signal in stomach glandular cells (HPA tissue IHC). This guide covers fixation, antibody conditions and interpretation of a secreted protein (datasheet A07594; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
GKN1 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 | Selective cytoplasmic staining in stomach (HPA tissue IHC) | |
| Staining pattern | Medium cytoplasmic staining in stomach glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A07594) | |
| Positive control | Stomach | |
| 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 | Secreted GKN1 may appear away from RNA-positive cells (HPA tissue IHC) | |
| Regulation | Not detected in gastric cancer tissue (UniProt) | |
| Isoform / epitope | No alternate isoforms; mature chain spans 21–185 (UniProt) |
Section 1
Recommended GKN1 IHC & IF Protocols
The catalog antibody has a datasheet IHC-P protocol (datasheet A07594); two published protocols provide additional conditions for gastric tissue and pancreas sections (PMC3511871; PMC8897191).
| Sample | Paraffin-embedded mouse stomach tissue; fixative not specified (datasheet A07594) |
| Fixation | Image fixative and duration unreported (datasheet A07594); 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 A07594); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A07594) |
| Primary antibody | Rabbit anti-GKN1, 2-5 μg/ml (datasheet A07594) |
| Primary incubation | Overnight at 4 °C (datasheet A07594) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A07594) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | GKN1-positive staining in glandular cells of stomach (HPA tissue IHC: Medium). HPA tissue profile: Selective cytoplasmic expression in stomach. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 for the catalog antibody (datasheet A07594). Use citrate at pH 6.0 when reproducing the gastric tissue protocol (PMC3511871).
Section 2
What Is the Expected GKN1 Staining Pattern?
GKN1 should stain the cytoplasm of stomach glandular cells at medium intensity, with granular staining and possible perinuclear accentuation (HPA: selective cytoplasmic expression; stomach glandular cells, Medium; UniProt Q9NS71: granular cytoplasm and Golgi-like accentuation). It is a secreted protein with no transmembrane segment, so membrane-restricted staining is unexpected (UniProt Q9NS71: topology). HPA rates the tissue IHC pattern Enhanced (HPA: tissue IHC reliability).
| Medium cytoplasmic staining in stomach glandular cells, granular with possible perinuclear accentuation. | This fits the reported positive tissue and compartment (HPA: stomach glandular cells, Medium; selective cytoplasmic expression). Perinuclear accentuation is compatible with the reported Golgi-like appearance (UniProt Q9NS71: subcellular note). Score the glandular cells and their cytoplasm, rather than treating any brown material in the section as a positive cell. |
| Signal appears chiefly nuclear or sharply confined to cell membranes. | That compartment does not match the reported granular cytoplasmic pattern or the absence of a transmembrane segment (UniProt Q9NS71: subcellular note; topology). Treat it as suspect staining and review morphology, controls, and detection background before assigning GKN1 positivity; the image alone cannot identify the artefact's cause. |
| Prominent staining appears in an unexpected cell population or in a reported negative tissue. | Consider cross-reactivity or endogenous detection activity, particularly if stomach glandular cells fail to show the expected pattern (HPA: selective stomach cytoplasmic expression). HPA reports no detection in appendix glandular cells and bronchus respiratory epithelial cells (HPA: tissue IHC). An unexpected positive is a reason to investigate, not proof of either mechanism. |
| Broad, hazy signal covers many cells or the surrounding section without a clear glandular-cell boundary. | This is difficult to score as GKN1 because HPA describes selective cytoplasmic expression in stomach (HPA: tissue IHC profile). Review background on a no-primary control and whether detection deposits or nonspecific binding obscure the cells. Do not equate extracellular colour alone with a positive cell: GKN1 is secreted (UniProt Q9NS71: subcellular annotation). |
| No convincing signal appears in the stomach glandular cells of a presumed positive section. | First establish that the section contains evaluable glandular cells; their reported staining is Medium, rather than uniformly strong (HPA: stomach glandular cells, Medium). If present, review the IHC-validated antibody, detection and general staining workflow. A single blank slide cannot distinguish a technical failure from reduced GKN1 in that sample. |
💡Expected GKN1 appearanceCall the slide positive when stomach glandular cells show medium granular cytoplasmic staining, possibly accentuated near the nucleus (HPA: stomach glandular cells, Medium; UniProt Q9NS71: subcellular note); isolated nuclear, membrane-only, or widespread hazy signal is suspect against that pattern (UniProt Q9NS71: topology; HPA: selective cytoplasmic expression).
| Cellular location and secretion | GKN1 is annotated as secreted and present in cytoplasmic granules and the Golgi apparatus (UniProt Q9NS71: subcellular location). Interpret cellular positivity through the glandular-cell cytoplasm; secretion alone cannot establish where extracellular chromogen should appear in a particular section. |
| Processing and membrane topology | The signal peptide spans residues 1–20, and the mature chain spans 21–185; no transmembrane segment is annotated (UniProt Q9NS71: processing; topology). The supplied record gives no antibody epitope, so it cannot predict which molecular form that antibody recognizes. |
| Tissue comparison and validation | HPA reports Medium staining in stomach glandular cells and no detection in the listed negative tissues (HPA: tissue IHC). Its tissue pattern is rated Enhanced, and HPA047684 has Enhanced IHC validation (HPA: reliability; antibody validation). These observations guide controls but do not establish every specimen's result. |
| Fixation and retrieval evidence | Target-specific fixation sensitivity and retrieval conditions are unreported in the supplied UniProt and HPA records. General IHC practice permits checking section processing and retrieval when staining fails, but these sources do not support a claim that either changes GKN1 staining. |
| IF/ICC interpretation | Q: Is there an established ICC-IF pattern to use here? A: HPA lists GKN1 as secreted but gives no main cellular location or cell lines with ICC-IF images (HPA: subcellular ICC-IF). Interpret any IF result cautiously against tissue IHC and the UniProt location annotation; no IF protocol is established by these records. |
| Situation | Likely cause | Next action |
|---|---|---|
| Stomach glandular cells are blank. | The section may lack evaluable glandular cells, or the IHC detection workflow may have failed; HPA's expected level is Medium (HPA: stomach glandular cells). | Check tissue morphology and a known-positive stomach section in the same run. Review antibody use, detection reagents and retrieval as general IHC workflow checks; the supplied sources give no GKN1-specific retrieval setting. |
| Staining is uniformly weak across the presumed positive section. | Weak signal could reflect general assay sensitivity or the sample's expression; HPA reports Medium staining in stomach glandular cells (HPA: tissue IHC). | Compare intact glandular cells with a positive control processed in the same run. Confirm that counterstain and chromogen allow cytoplasmic signal to be seen, then adjust the general IHC workflow using validated local controls. |
| Nuclei or cell borders stain more strongly than the cytoplasm. | That distribution conflicts with the reported granular cytoplasmic appearance and lack of a transmembrane segment (UniProt Q9NS71: subcellular note; topology). | Inspect the no-primary control and section morphology. Reassess antibody specificity and detection background before scoring; do not reinterpret nuclear or membrane-only signal as the expected GKN1 pattern. |
| Unexpected cells or reported negative tissues stain. | Cross-reactivity or endogenous detection activity is possible; HPA describes selective stomach cytoplasmic expression and lists negative tissues (HPA: tissue IHC). | Compare staining with a no-primary control and an appropriate negative tissue from the HPA list, such as appendix or bronchus (HPA: tissue IHC). For chromogenic detection, assess endogenous enzyme activity using standard IHC controls. |
| Diffuse chromogen makes individual positive cells hard to identify. | Background from binding or detection may obscure the selective glandular cytoplasmic pattern (HPA: tissue IHC profile); GKN1 secretion complicates interpretation of extracellular material (UniProt Q9NS71: subcellular location). | Check the no-primary control, blocking and detection steps as general IHC practice. Score only identifiable cells with convincing cytoplasmic staining, and record extracellular or diffuse colour separately as uncertain. |
| IF/ICC shows puncta or perinuclear fluorescence, but cell identity is unclear. | UniProt reports granules and Golgi-like accentuation, while HPA supplies no ICC-IF image-based cellular pattern (UniProt Q9NS71: subcellular note; HPA: subcellular ICC-IF). | Use nuclear and cell-boundary counterstains to locate fluorescence within cells, and compare suitable fluorescence controls. Treat agreement with the UniProt description as supportive, without claiming HPA ICC-IF validation or deriving an IF protocol from it. |
Experiment evidence
IHC & IF images showing GKN1 staining
A07594 · IHCIHC analysis of GKN1 using anti-GKN1 antibody (A07594). GKN1 was detected in a paraffin-embedded section of mouse stomach tissue. Heat media
A07594 · IHCIHC analysis of GKN1 using anti-GKN1 antibody (A07594). GKN1 was detected in a paraffin-embedded section of human stomach tissue. Heat media
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000169605-GKN1/tissue/cerebral+cortex#imid_17583775
HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000169605-GKN1/tissue/stomach+2#imid_17583649
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000169605-GKN1/tissue/colon#imid_17583691
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000169605-GKN1/tissue/liver#imid_17583692
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for GKN1 IHC & IF
🧪Run stomach first: glandular cells should stain (HPA: Medium in stomach glandular cells). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); on the stomach slide, assess cells outside the glands as an internal background reference rather than assuming every cell is positive (HPA: staining reported in glandular cells).
Positive control tissue: Stomach (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for GKN1; derive a cell-line control from the positive tissue's cell type (Glandular cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit IgG isotype control matched to the primary antibody’s clonality where known (selected-SKU caption: rabbit primary). Use GKN1 knockout tissue, if available, as a biological negative; block endogenous peroxidase for HRP–DAB detection in stomach sections (selected-SKU caption: HRP–DAB).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected-SKU paraffin-section caption does not state a fixative (selected-SKU caption: fixative not stated). The mouse-stomach example uses heat retrieval in EDTA at pH 8.0, but does not establish that retrieval is required (selected-SKU caption: EDTA pH 8.0). Frozen sections and IF have no matched evidence showing they are easier; because GKN1 is secreted, distinguish glandular-cell staining from luminal or extracellular signal when scoring (HPA: no ICC-IF cell-line images; UniProt Q9NS71: secreted).
HPA tissue IHC evidence for GKN1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data. Secreted protein, tissue location of RNA and protein is expected to differ.). 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 |
|---|---|---|---|---|
| Stomach | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced GKN1 IHC Tips
Troubleshoot GKN1 staining in paraffin sections by checking tissue controls, processing conditions, cellular localisation and detection background.
What retrieval should I try first if GKN1 staining is weak?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin-section GKN1 IHC (datasheet A07594). The selected mouse stomach image used that retrieval, followed by 10% goat-serum blocking, 2 μg/mL primary antibody overnight at 4°C, and DAB detection (datasheet A07594). Its caption specifies neither a fixative nor a heating duration, so record both when comparing sections (datasheet A07594; standard IHC practice). If signal remains weak, compare a slightly longer heating interval or a citrate-buffer fallback on matched sections while holding detection conditions constant (standard IHC practice). Reject apparent gains that damage glandular morphology or obscure cytoplasmic staining (HPA: stomach glandular cells, cytoplasmic expression; standard IHC practice).
Could fixation explain weak or inconsistent GKN1 staining?
The selected tissue image identifies a paraffin-embedded mouse stomach section but does not report its fixative (datasheet A07594). Target-specific fixation sensitivity is therefore unknown; neither the stomach staining pattern nor the protein’s topology establishes a preferred fixation condition (HPA: selective stomach cytoplasmic expression; UniProt Q9NS71 topology). For troubleshooting, document fixative, time before fixation, fixation duration and section age for each specimen, then compare matched sections processed together (standard IHC practice). Keep retrieval at EDTA pH 8.0 during that comparison so fixation is the main variable (datasheet A07594; standard IHC practice). Interpret any difference as a processing observation until repeated across matched samples (standard IHC practice).
Where should convincing GKN1 staining appear within gastric tissue?
Look first for cytoplasmic staining in stomach glandular cells; the tissue reference reports medium staining there and selective cytoplasmic expression in stomach (HPA: stomach glandular cells, Medium; selective cytoplasmic expression). Granular cytoplasmic signal with perinuclear accentuation is plausible because GKN1 is annotated to cytoplasmic granules and the Golgi apparatus (UniProt Q9NS71 localisation). Its secreted annotation also means extracellular material requires careful assessment against adjacent cellular signal (UniProt Q9NS71 localisation; standard IHC practice). Do not score isolated nuclear or sharp plasma-membrane staining as the expected pattern without independent validation (UniProt Q9NS71 localisation and topology). Compare the glandular pattern with a negative tissue and a no-primary control before assigning faint deposits to GKN1 (HPA: adipose tissue, Not detected; standard IHC practice).
How should epitope uncertainty affect retrieval and staining interpretation?
The supplied record lists one GKN1 chain, residues 21–185, after a 1–20 signal peptide, and lists 0 isoforms (UniProt Q9NS71 processing and isoforms). It also lists a BRICHOS domain at residues 54–150, no transmembrane segment, and no annotated glycosylation sites (UniProt Q9NS71 domains, topology and glycosylation). The selected caption does not specify the antibody’s recognized epitope, so those features cannot establish which processing condition preserves binding (datasheet A07594; UniProt Q9NS71 processing). Begin with EDTA pH 8.0 retrieval and the caption’s 2 μg/mL primary concentration (datasheet A07594). If staining differs between samples, compare matched processing and an independently validated reagent before attributing the difference to an isoform or modification (standard IHC practice; UniProt Q9NS71 isoforms).
How can I investigate GKN1 by multiplex IF after chromogenic IHC?
Use the stomach glandular-cell pattern seen by chromogenic IHC as a reference, then pair GKN1 with a separately validated glandular-cell marker for multiplex IF (HPA: stomach glandular cells, cytoplasmic expression; standard IF practice). Choose a bright fluorophore in a channel with low measured tissue autofluorescence, and inspect unstained sections before setting exposure or spectral separation (standard IF practice). Because GKN1 is annotated as secreted and associated with cytoplasmic granules and Golgi, test gentle permeabilisation when the antibody must access intracellular epitopes (UniProt Q9NS71 localisation; standard IF practice). Epitope accessibility cannot be specified without the antibody’s epitope information (datasheet A07594). Keep single-stain and no-primary controls to distinguish overlap and background from genuine cellular colocalisation (standard IF practice).
How do I reduce diffuse brown staining without losing GKN1 signal?
Start by checking a no-primary section and a tissue expected to lack detectable staining, such as adipose tissue, alongside stomach (HPA: adipose tissue, Not detected; stomach glandular cells, Medium; standard IHC practice). The selected image used 10% goat serum, 2 μg/mL primary overnight at 4°C, a peroxidase-conjugated secondary, and DAB (datasheet A07594). Apply an endogenous-peroxidase block and optimise DAB development as general chromogenic IHC controls, especially when brown deposits appear without primary antibody (standard IHC practice). If background persists, compare shorter primary incubation or lower antibody concentration on matched sections while retaining a positive stomach control (standard IHC practice; HPA: stomach glandular cells). Score cell-associated cytoplasmic signal separately from diffuse surface precipitate (HPA: selective cytoplasmic expression; standard IHC practice).
How should I quantify GKN1 IHC across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the stomach glandular-cell compartment before scoring, because the reference signal is selective and cytoplasmic in those cells (HPA: stomach glandular cells, Medium; selective cytoplasmic expression). Record the percentage of positive glandular cells and staining intensity, or combine them as an H-score from 0–300 using intensity grades 0–3 (standard IHC practice). Normalise positive-cell counts to the total evaluable glandular-cell count, and report stained area or cell density per mm² of viable glandular tissue (standard IHC practice). Use identical retrieval, exposure-independent chromogen development criteria, and threshold settings across the comparison set (datasheet A07594: EDTA pH 8.0; standard IHC practice). Exclude folds, edges and necrotic regions by a prespecified rule (standard IHC practice).
Which staining patterns support a true GKN1 positive result?
A credible positive follows the stomach glandular-cell distribution and cytoplasmic pattern reported for GKN1 (HPA: stomach glandular cells, Medium; selective cytoplasmic expression). Granular staining with perinuclear accentuation is consistent with its annotated cytoplasmic-granule and Golgi localisation (UniProt Q9NS71 localisation). Treat isolated nuclear or membrane-rim signal, edge-only staining and deposits over necrosis as suspect until reproduced in intact glands (UniProt Q9NS71 localisation and topology; standard IHC practice). A brown signal in a no-primary section suggests endogenous enzyme activity or detection-system background rather than antigen-specific staining (standard IHC practice). Compare a positive stomach section, a negative tissue and matched morphology before concluding that weak or absent staining reflects biology (HPA: stomach glandular cells, Medium; adipose tissue, Not detected; standard IHC practice).
Boster reagents
Best GKN1 / Gastrokine-1 IHC Antibodies
A07594 has real IHC data from paraffin sections of human and mouse stomach (catalog IHC captions); no IF data are supplied (catalog IF images: none).
Real IHC data
Anti-GKN1 Antibody ®
Cat # A07594
A07594 is listed for IHC and reacts with human and mouse (catalog applications and reactivity). Its IHC captions show staining in paraffin sections of human and mouse stomach (catalog IHC captions).
Which to pick: Choose A07594 for paraffin-section tissue IHC, including human or mouse stomach samples: its own captions document EDTA retrieval at pH 8.0 and staining at 2 μg/ml (A07594 IHC captions). No IF/ICC application or image is supplied, so IF/ICC suitability is unvalidated in this payload (catalog applications and IF images). The captions identify paraffin sections but do not report the fixative (A07594 IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9NS71 (GKN1_HUMAN, Gastrokine-1).
- Human Protein Atlas. GKN1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. GKN1 subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. GKN1 antibody validation summary (1 antibodies).
- Downregulation of gastrokine-1 in gastric cancer tissues and restoration of its expression induced gastric cancer cells to apoptosis. Journal of experimental & clinical cancer research : CR 2012 — PMC3511871.
- De novo expression of gastrokines in pancreatic precursor lesions impede the development of pancreatic cancer. Oncogene 2022 — PMC8897191.
- Decreased expression of gastrokine 1 and the trefoil factor interacting protein TFIZ1/GKN2 in gastric cancer: influence of tumor histology and relationship to prognosis. Clinical cancer research : an official journal of the American Association for Cancer Research 2008 — PMC2572195.
- Gastrokine 1 regulates NF-κB signaling pathway and cytokine expression in gastric cancers. Journal of cellular biochemistry 2013 — PMC3713628.
- PubMed PMID:10835488 — UniProt-cited evidence.
- PubMed PMID:12851218 — UniProt-cited evidence.
- PubMed PMID:15815621 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for GKN1 (Gastrokine-1). Expected localisation Selective cytoplasmic staining in stomach (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A07594). Validated IHC antibody: A07594 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Stomach (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse stomach tissue; fixative not specified (datasheet A07594); 2. Fixation: Image fixative and duration unreported (datasheet A07594); 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 A07594); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A07594); 8. Primary antibody: Rabbit anti-GKN1, 2-5 μg/ml (datasheet A07594); 9. Primary incubation: Overnight at 4 °C (datasheet A07594). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Secreted GKN1 may appear away from RNA-positive cells (HPA tissue IHC); Isoform / epitope: No alternate isoforms; mature chain spans 21–185 (UniProt); Regulation: Not detected in gastric cancer tissue (UniProt). Evidence: UniProt Q9NS71, HPA tissue IHC · Enhanced, HPA ICC-IF · Secreted, Datasheet A07594, PMC3511871, PMC8897191. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/GKN1/immunohistochemistry-ihc-guide.