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KCNJ5 / G protein-activated inward rectifier potassium channel 4 · IHC design guide
Design Immunohistochemistry for KCNJ5
Plan chromogenic KCNJ5 IHC in paraffin sections using adrenal glandular cells as a strong positive reference (HPA tissue IHC). This guide covers fixation, antibody use, and interpretation of observed cytoplasmic staining alongside the protein’s membrane topology (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
KCNJ5 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 (HPA tissue IHC); membrane protein (UniProt) | |
| Staining pattern | Glandular cell cytoplasm, strongest in adrenal gland (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A02160) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Bone marrow+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 | Antibody staining has low consistency with RNA data (HPA tissue IHC) | |
| Regulation | Adrenal and pancreas RNA enrichment (HPA tissue RNA) | |
| Isoform / epitope | No annotated isoforms; epitope side affects access (UniProt) |
Section 1
Recommended KCNJ5 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A02160) is paired with published KCNJ5 protocols for FFPE adrenal tissue (PMC6739168; PMC12185499; PMC11787464).
| Sample | Paraffin-embedded human cervical carcinoma tissue; fixative not specified (datasheet A02160) |
| Fixation | Image fixative and duration unreported (datasheet A02160); 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 9.0 (datasheet A02160); 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-KCNJ5, 1:50 recommended; image 1:200 (datasheet A02160) |
| 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 | KCNJ5-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several tissues with strongest expression in adrenal gland. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated Tris-EDTA pH 9.0 retrieval (datasheet A02160); citrate pH 6 is another published condition (PMC11787464 methods).
Section 2
What Is the Expected KCNJ5 Staining Pattern?
KCNJ5 (GIRK4) is a membrane protein with two transmembrane segments (UniProt P48544 topology). In paraffin-section IHC, HPA describes predominantly cytoplasmic staining, strongest in adrenal glandular cells and also high in pancreatic exocrine glandular cells (HPA tissue IHC). Treat these as observed staining patterns, not proof of precise membrane localisation: HPA rates the tissue IHC evidence Approved but reports low consistency with RNA expression (HPA tissue IHC).
| Strong staining in adrenal glandular cells, with cytoplasmic signal and possible membrane enrichment (HPA tissue IHC; UniProt P48544 topology). | This fits the strongest reported tissue pattern (HPA: High in adrenal glandular cells). Record cytoplasmic and membrane-associated signal separately; the channel topology supports membrane localisation, while the HPA IHC description calls the observed staining cytoplasmic (UniProt P48544 topology; HPA tissue IHC). |
| Predominantly nuclear staining, with little signal in the expected cytoplasmic or membrane-associated area. | A nuclear-only pattern conflicts with KCNJ5 membrane topology and the reported cytoplasmic IHC profile (UniProt P48544 topology; HPA tissue IHC). Check the negative control and repeat staining before assigning it to KCNJ5 (general IHC practice). |
| Strong staining in squamous epithelial cells of esophagus or oral mucosa (HPA: Not detected in those cells). | That distribution conflicts with the reported tissue pattern and may indicate nonspecific antibody binding or endogenous detection activity; it does not establish either cause by itself (HPA tissue IHC; general IHC practice). Compare a no-primary control and the glandular-cell pattern (general IHC practice). |
| Broad, fairly uniform chromogen across tissue and extracellular spaces, obscuring cell boundaries. | This is more consistent with staining background than an interpretable cell-specific pattern (general IHC practice). It prevents comparison with HPA's glandular-cell staining levels; assess the no-primary control before scoring cells (HPA tissue IHC; general IHC practice). |
| No detectable staining in well-preserved adrenal glandular cells (HPA: High in adrenal glandular cells). | A negative result in this expected positive tissue is inconclusive until the run controls and antibody performance are checked (HPA tissue IHC; general IHC practice). HPA's Approved rating comes with low staining-to-RNA consistency, so it is not a guarantee that every section will stain (HPA tissue IHC). |
💡Expected KCNJ5 appearanceCall a positive result when adrenal glandular cells show strong cytoplasmic staining, with membrane enrichment permissible; isolated nuclear signal or equally strong staining in HPA-negative squamous cells is suspect (HPA tissue IHC; UniProt P48544 topology).
| Observed compartment versus channel topology | HPA describes cytoplasmic tissue IHC, whereas UniProt assigns KCNJ5 to membranes with two transmembrane segments; score the observed cytoplasmic pattern without claiming that chromogenic IHC resolves the channel's exact membrane boundary (HPA tissue IHC; UniProt P48544 topology). |
| Tissue and cell context | Adrenal glandular cells and pancreatic exocrine glandular cells are High; appendix, breast, cervix, colon, duodenum and endometrial glandular cells are Medium (HPA tissue IHC). Compare like cell populations when judging intensity (general IHC practice). |
| Epitope location, if supplied for the chosen antibody | UniProt places residues 1–86 and 186–419 on the cytoplasmic side and residues 112–135 and 155–163 extracellularly (UniProt P48544 topology). The antibody epitope is unspecified here, so topology alone cannot predict retrieval requirements or staining strength. |
| Strength of tissue evidence | All three listed antibodies have Approved IHC status; the tissue profile also reports low consistency between staining and RNA expression (HPA antibodies; HPA tissue IHC). Use the reported distribution as a comparison, then interpret unexpected staining with controls rather than treating it as definitive expression. |
| IF/ICC: should the same appearance be expected? | HPA summarises subcellular location as Membrane but lists no ICC-IF image cell lines or ICC validation for the three antibodies (HPA subcellular; HPA antibodies). IF/ICC localisation therefore cannot be verified from these payloads; consult its separate guide for that application. |
| Situation | Likely cause | Next action |
|---|---|---|
| Adrenal glandular cells are unstained (HPA: High). | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. | Check positive and no-primary controls, reagent delivery and detection steps; document the result as unresolved if controls work (general IHC practice). |
| Pancreatic exocrine glandular cells stain weakly or unevenly (HPA: High). | Field selection or uneven section staining can confound comparison with the reported High category (HPA tissue IHC; general IHC practice). | Inspect multiple intact exocrine fields and compare their background and counterstain before scoring intensity (general IHC practice). |
| Nuclei carry the dominant chromogenic signal. | A nuclear-only distribution is discordant with the reported cytoplasmic IHC profile and membrane topology (HPA tissue IHC; UniProt P48544 topology). | Check the no-primary control and antibody staining conditions; withhold a KCNJ5-positive call unless the expected cellular pattern appears (general IHC practice). |
| HPA-negative squamous cells stain strongly. | Nonspecific binding or endogenous detection activity is possible; esophageal and oral squamous epithelial cells are reported Not detected (HPA tissue IHC; general IHC practice). | Use no-primary and detection controls to localise background, then reassess the glandular-cell pattern under the same run conditions (general IHC practice). |
| Diffuse chromogen makes individual cells hard to score. | Excess background can obscure the cell-specific distribution needed for interpretation (general IHC practice). | Review control sections and the detection and wash steps; score only fields where cells and subcellular signal remain distinguishable (general IHC practice). |
| An IF image appears membrane-localised, but the IHC section looks cytoplasmic. | Those descriptions come from different HPA summaries; the supplied record has no ICC-IF image cell lines for direct comparison (HPA tissue IHC; HPA subcellular). | Report each application and its controls separately; do not use the IF summary to overrule an interpretable paraffin-section IHC result (HPA tissue IHC; HPA subcellular; general IHC practice). |
Experiment evidence
IHC & IF images showing KCNJ5 staining
A02160 · IHCImmunohistochemical analysis of paraffin-embedded human cervical carcinoma. 1, Antibody was diluted at 1:200(4° overnight). 2, Tris-EDTA,pH9
A02160 · IFImmunofluorescence analysis of A549 cells, using KCNJ5 Antibody. The picture on the right is blocked with the synthesized peptide.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000120457-KCNJ5/tissue/cerebral+cortex#imid_4596896
HPA · Adrenal glandHuman Protein Atlas IHC, Adrenal gland. Source: https://www.proteinatlas.org/ENSG00000120457-KCNJ5/tissue/adrenal+gland#imid_4596880
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000120457-KCNJ5/tissue/colon#imid_4596830
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000120457-KCNJ5/tissue/liver#imid_4596823
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for KCNJ5 IHC & IF
🧪Run adrenal gland first: glandular cells should stain (HPA: High in adrenal gland glandular cells). Use bone marrow hematopoietic cells as the negative tissue (HPA: Not detected); on the adrenal slide, use neighboring nonglandular cells as internal background comparators and check for convincing membrane staining (UniProt P48544: Membrane).
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: Bone marrow (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for KCNJ5; 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 isotype control from the primary antibody’s host species and immunoglobulin class; use KCNJ5 knockout tissue or cognate-peptide competition, if available, to test specificity. On adrenal sections (HPA: High in glandular cells), quench endogenous peroxidase and block endogenous biotin if using avidin–biotin detection.
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported in the supplied evidence; the selected A02160 paraffin-section caption does not state a fixative (datasheet: fixative not stated). The caption uses Tris-EDTA at pH 9.0 for antigen retrieval, but does not establish that retrieval is required for every specimen (datasheet: Tris-EDTA, pH 9.0). Frozen sections or IF cannot be identified as easier from the supplied evidence; IF has no listed HPA cell-line images (HPA: no cell lines with ICC-IF images), and adrenal sections warrant checks for endogenous peroxidase and, with avidin–biotin detection, endogenous biotin (HPA: High in adrenal gland glandular cells).
HPA tissue IHC evidence for KCNJ5
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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Pancreas | Exocrine glandular cells | High | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Oral mucosa | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Skeletal muscle | Myocytes | Not detected | Protein (IHC) | HPA → |
| Vagina | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced KCNJ5 IHC Tips
Troubleshoot KCNJ5 chromogenic IHC in paraffin sections using the catalog antibody’s tissue image, protein topology, and tissue staining patterns as distinct evidence sources.
What retrieval should I try first when KCNJ5 staining is weak?
Start with heat-mediated Tris-EDTA retrieval at pH 9.0 (datasheet A02160). The catalog antibody’s paraffin-section image used that retrieval, primary antibody at 1:200 overnight at 4°C, and secondary antibody at 1:200 for 45 minutes at room temperature (caption A02160). Keep those conditions together for an initial comparison, then vary retrieval heating and cooling consistently across matched sections if signal remains weak (standard IHC practice). Record tissue preservation alongside staining intensity, because overly harsh heat can impair morphology and make glandular-cell scoring unreliable (standard IHC practice).
How should I troubleshoot variable KCNJ5 staining across differently fixed specimens?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative (caption A02160). Record each specimen’s fixative, fixation duration, processing history, and section age before comparing chromogenic intensity (standard IHC practice). Process matched sections through the same Tris-EDTA pH 9.0 retrieval and detection run, including a reference section when available (datasheet A02160; standard IHC practice). If a fixation group stains differently, repeat the comparison with matched tissue and controls before attributing the difference to KCNJ5 abundance; fixation and processing can alter antigen accessibility in IHC generally (standard IHC practice).
Should KCNJ5 appear at the membrane or in the cytoplasm?
KCNJ5 is annotated as a membrane protein with transmembrane segments at residues 87–111 and 164–185 (UniProt P48544 topology). Tissue IHC reports predominantly cytoplasmic staining, strongest in adrenal gland, while its subcellular summary says membrane and provides no ICC/IF images (HPA tissue IHC; HPA subcellular). Score membranous and cytoplasmic chromogen separately, with the same compartment definitions applied to every section (standard IHC practice). Diffuse cytoplasmic color alone cannot establish membrane localization; compare cellular distribution, morphology, and staining controls before assigning a specific compartment (UniProt P48544 topology; standard IHC practice).
How can epitope position change what I see in paraffin-section IHC?
The record lists 0 annotated isoforms and a 419-residue chain; this does not identify the catalog antibody’s epitope (UniProt P48544). KCNJ5 has cytoplasmic regions at residues 1–86 and 186–419, with extracellular regions at 112–135 and 155–163 (UniProt P48544 topology). Check the antibody’s documented immunogen or epitope before interpreting a weak signal as loss of a particular region, and compare staining after the specified pH 9.0 retrieval (datasheet A02160; standard IHC practice). A phosphoserine is annotated at residue 5, but the payload provides no evidence that this modification changes IHC recognition (UniProt P48544).
How should I adapt this KCNJ5 tissue question to a multiplex IF experiment?
Treat IF as a separate assay: the supplied antibody image documents chromogenic paraffin-section IHC, and the HPA subcellular record lists no ICC/IF images (caption A02160; HPA subcellular). Multiplex KCNJ5 with a validated marker for the glandular cells being examined; glandular adrenal cells show high tissue-IHC staining (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores after checking tissue autofluorescence, favoring a red or far-red channel for a weak target when background permits (standard IF practice). Set permeabilisation according to the verified epitope: cytoplasmic regions require intracellular access, whereas extracellular epitopes may be assessed without it (UniProt P48544 topology; standard IF practice). Include single-color and secondary-only controls (standard IF practice).
What should I change when KCNJ5 chromogenic staining has diffuse background?
First compare a no-primary control with the stained section to identify signal from secondary detection or tissue chemistry (standard IHC practice). For a peroxidase and DAB workflow, include a peroxidase block, appropriate nonspecific-binding block, and thorough washes; these are general IHC steps, not KCNJ5-specific validation (standard IHC practice). The catalog image used primary antibody at 1:200 overnight at 4°C and secondary at 1:200 for 45 minutes at room temperature (caption A02160). If background persists, titrate detection conditions on matched sections while checking whether expected glandular staining remains distinguishable (HPA tissue IHC; standard IHC practice).
How should I quantify KCNJ5 staining without mixing compartments or cell populations? ⚠ ANSWER MARKED FOR VERIFICATION
Define the glandular-cell region and the membranous and cytoplasmic compartments before scoring, then apply those definitions consistently across sections (HPA tissue IHC; UniProt P48544 topology; standard IHC practice). Report the percentage of positive glandular cells and an H-score from 0–300, calculated as the sum of each intensity grade multiplied by its percentage of cells (standard IHC practice). If measuring positive-cell density per mm², normalize to the evaluable glandular area and exclude necrotic or damaged regions (standard IHC practice). Compare specimens processed and imaged under matched conditions, and report compartment-specific scores because HPA describes cytoplasmic tissue staining while UniProt annotates a membrane protein (HPA tissue IHC; UniProt P48544).
How do I distinguish credible KCNJ5 staining from a tissue artefact?
Look for reproducible staining in the expected glandular cells: HPA reports high staining in adrenal glandular cells and pancreatic exocrine glandular cells (HPA tissue IHC). Assess membrane-associated signal separately from cytoplasmic color, because UniProt annotates a membrane protein while HPA describes cytoplasmic tissue-IHC staining (UniProt P48544; HPA tissue IHC). Discount staining confined to section edges, necrotic areas, or sites positive in a no-primary or peroxidase-control section (standard IHC practice). A paraffin-section cervical carcinoma image demonstrates staining with SKU A02160, but its fixative is unreported; interpret that example alongside controls and HPA’s stated low consistency between staining and RNA expression (caption A02160; HPA tissue IHC).
Boster reagents
Best KCNJ5 / G protein-activated inward rectifier potassium channel 4 IHC Antibodies
A02160 has a paraffin-section IHC image of human cervical carcinoma and an IF image of A549 cells (catalog image captions). Listed reactivity covers Human, Mouse, and Rat (catalog reactivity).
Real IHC data
Anti-KCNJ5/Kir3.4 Antibody
Cat # A02160
A02160 will render with its IHC figure of paraffin-embedded human cervical carcinoma (A02160 IHC image caption). The catalog also supplies an A549-cell IF image, although IF/ICC is absent from the listed applications (catalog IF image caption; catalog applications).
Which to pick: Choose A02160 for tissue IHC: it is a rabbit polyclonal with IHC listed, and its own figure used Tris–EDTA at pH 9.0 for antigen retrieval on paraffin-embedded sections (catalog host, dilution_raw, applications; A02160 IHC image caption). For IF/ICC, A02160 has an A549-cell image, but its application list does not include IF/ICC, so confirm suitability before use (catalog IF image caption; catalog applications). A02160 lists Human, Mouse, and Rat reactivity for cross-species planning; the fixative used for its IHC figure is unreported (catalog reactivity; A02160 IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P48544 (KCNJ5_HUMAN, G protein-activated inward rectifier potassium channel 4).
- Human Protein Atlas. KCNJ5 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. KCNJ5 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. KCNJ5 antibody validation summary (3 antibodies).
- Primary Aldosteronism: KCNJ5 Mutations and Adrenocortical Cell Growth. Hypertension (Dallas, Tex. : 1979) 2019 — PMC6739168.
- Histopathological spectrum of common aldosterone-driver gene mutations in aldosterone-producing adenomas. Frontiers in medicine 2025 — PMC12185499.
- Double CYP11B1/CYP11B2 Immunohistochemistry and Detection of KCNJ5 Mutations in Primary Aldosteronism. The Journal of clinical endocrinology and metabolism 2024 — PMC11918620.
- EGR1 regulates oxidative stress and aldosterone production in adrenal cells and aldosterone-producing adenomas. Redox biology 2025 — PMC11787464.
- PubMed PMID:8047164 — UniProt-cited evidence.
- PubMed PMID:8524415 — UniProt-cited evidence.
- PubMed PMID:8868049 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for KCNJ5 (G protein-activated inward rectifier potassium channel 4). Expected localisation Cytoplasmic staining (HPA tissue IHC); membrane protein (UniProt). Antigen retrieval: Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A02160). Validated IHC antibody: A02160 at 1:50 recommended; image 1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Bone marrow. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human cervical carcinoma tissue; fixative not specified (datasheet A02160); 2. Fixation: Image fixative and duration unreported (datasheet A02160); 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 9.0 (datasheet A02160); 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-KCNJ5, 1:50 recommended; image 1:200 (datasheet A02160); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Antibody staining has low consistency with RNA data (HPA tissue IHC); Isoform / epitope: No annotated isoforms; epitope side affects access (UniProt); Regulation: Adrenal and pancreas RNA enrichment (HPA tissue RNA). Evidence: UniProt P48544, HPA tissue IHC · Approved, HPA ICC-IF · Membrane, Datasheet A02160, PMC6739168, PMC12185499. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/KCNJ5/immunohistochemistry-ihc-guide.