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NKX3-2 / Homeobox protein Nkx-3.2 · IHC design guide
Design Immunohistochemistry for NKX3-2
Plan NKX3-2 IHC-P around nuclear tissue staining (HPA tissue IHC), starting the catalog antibody at 5 μg/mL (datasheet). Keep fixation consistent and interpret staining with the reported low agreement with RNA expression in mind (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
NKX3-2 Immunohistochemistry Experimental Design Guide
Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before staining
| Expected localisation | Nuclear staining in tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining across all tissues (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 | Low consistency between staining and RNA expression (HPA tissue IHC) | |
| Regulation | No stimulus-linked regulation annotated (UniProt) | |
| Isoform / epitope | No isoforms or processing annotated; epitope effects unknown (UniProt) |
Section 1
Recommended NKX3-2 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by one published NKX3-2 IHC protocol using human hepatocellular carcinoma sections (PMC11104445).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A07429); 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-NKX3-2, 5 μg/mL (datasheet A07429) |
| 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 | NKX3-2-positive staining in adipocytes of adipose tissue (HPA tissue IHC: Medium). HPA tissue profile: Nuclear expression in all tissues. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 retrieval at 95–98 °C for 20 min (page retrieval rule; UniProt P78367: nucleus). The published protocol does not state retrieval (PMC11104445).
Section 2
What Is the Expected NKX3-2 Staining Pattern?
NKX3-2 is a nuclear transcriptional repressor with no transmembrane segment (UniProt P78367). In paraffin IHC, expect nuclear staining in tissue cells, including the glandular cells, adipocytes, respiratory epithelial cells and hematopoietic cells reported at medium intensity by HPA (HPA: tissue IHC). HPA describes nuclear expression across tissues, but rates its IHC evidence Approved with low consistency between antibody staining and RNA expression; interpret a positive result with that limitation (HPA: tissue IHC reliability).
| Discrete nuclear staining in appendix glandular cells, with limited cytoplasmic signal. | This fits the expected compartment and an HPA-reported medium-staining cell population (UniProt P78367: nucleus; HPA: appendix glandular cells, Medium). Assess the nuclei alongside the tissue structure and counterstain; intensity alone does not confirm specificity (general IHC practice; HPA: low IHC–RNA consistency). |
| Predominantly cytoplasmic or membrane-associated staining, with little nuclear signal. | This conflicts with the reported nuclear location and absence of a transmembrane segment (UniProt P78367: nucleus, topology). Treat it as possible nonspecific staining or detection artefact; inspect the negative control and repeat with adjusted detection conditions before interpreting it as NKX3-2 (general IHC practice). |
| Strong signal in a cell population outside the HPA-reported pattern. | Check cell identity and the nuclear compartment first (general IHC practice; HPA: nuclear expression). Unexpected staining can reflect cross-reactivity or endogenous detection activity, but HPA reports nuclear expression across tissues, so an unlisted cell population is not, by itself, proof of a false positive (general IHC practice; HPA: tissue IHC profile). |
| Broad haze or widespread signal that obscures nuclear boundaries. | The pattern cannot be scored reliably as nuclear staining (general IHC practice; UniProt P78367: nucleus). Excess primary antibody, incomplete blocking or residual detection reagent are general IHC possibilities; compare the negative control and optimize one staining step at a time (general IHC practice). |
| No nuclear signal in appendix glandular cells or another HPA medium-staining population. | Check tissue preservation, retrieval, antibody application and detection with appropriate controls (general IHC practice). HPA reports medium staining in these populations, but its low IHC–RNA consistency limits how confidently one section can serve as a positive control (HPA: tissue IHC, reliability). |
💡Expected NKX3-2 appearanceA positive result is discernible nuclear chromogen in identifiable cells, potentially medium in HPA-listed populations; diffuse cytoplasmic, membranous or control-matched staining warrants investigation (UniProt P78367: nucleus; HPA: tissue IHC; general IHC practice).
| Subcellular location and topology | NKX3-2 is nuclear and has no transmembrane segment (UniProt P78367). Score staining within nuclei; membrane-dominant signal does not match the supplied target annotation (general IHC practice; UniProt P78367: topology). |
| Tissue pattern and evidence strength | HPA reports nuclear expression across tissues, medium staining in its listed cell populations and low staining in spleen red pulp cells (HPA: tissue IHC). Its Approved rating includes low consistency with RNA expression, so tissue intensity is a guide, not a specificity test (HPA: reliability). |
| Antibody validation | The supplied antibody record lists HPA027564 as Approved for IHC and ICC, without an Enhanced IHC designation (HPA: antibodies). Interpret its staining with slide controls and morphology; the supplied record does not establish independent reproduction of the IHC pattern (HPA: antibodies; general IHC practice). |
| Processing and epitope limits | UniProt lists no signal peptide, propeptide, annotated glycosylation sites or modified residues, and one chain spanning residues 1–333 (UniProt P78367). The supplied sources give no antibody epitope or target-specific retrieval sensitivity, so they do not justify a target-specific retrieval setting (UniProt P78367; HPA: antibodies). |
| IF/ICC cross-check? | HPA reports approved nucleoplasmic localization by ICC-IF, with images from HAP1, THP-1, U2OS and NIH 3T3 (HPA: subcellular, antibodies). Use that compartment as a comparison when reviewing IF/ICC results; those cell images do not establish an IHC intensity threshold (HPA: subcellular; general IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected nuclear staining is absent in appendix glandular cells. | The section or general IHC workflow may have failed; HPA's medium appendix result is qualified by low IHC–RNA consistency (general IHC practice; HPA: appendix, reliability). | Check tissue morphology, positive and negative controls, retrieval, primary antibody application and detection in that order (general IHC practice). Avoid declaring biological absence from one failed section (general IHC practice). |
| Signal is cytoplasmic or outlines cell membranes. | The compartment conflicts with UniProt's nuclear location and lack of a transmembrane segment (UniProt P78367). Nonspecific antibody or detection staining is possible (general IHC practice). | Compare a negative control, verify nuclear boundaries with the counterstain and adjust antibody or detection conditions if control staining persists (general IHC practice). |
| Nuclei and surrounding tissue share a diffuse brown haze. | Background can obscure the reported nuclear pattern (UniProt P78367: nucleus). Incomplete blocking, excess antibody or residual reagent are general IHC possibilities (general IHC practice). | Inspect the negative control, improve blocking or washes as indicated, and titrate the primary antibody within its validated IHC use (general IHC practice; HPA: antibody IHC Approved). |
| Unlisted cells stain strongly while expected cells are weak. | Cell identification, cross-reactivity or endogenous detection activity may explain the difference (general IHC practice). HPA also reports nuclear expression across tissues, so an unlisted cell is not automatically negative (HPA: tissue IHC profile). | Confirm morphology and nuclear location, then compare negative controls and HPA-listed cell populations on the same run (general IHC practice; HPA: tissue IHC). |
| Spleen red pulp appears weak or absent. | HPA reports low staining in red pulp cells, rather than a negative designation (HPA: spleen red pulp, Low; HPA: negative list empty). | Use a listed medium-staining population to assess whether the run produced detectable nuclear signal; do not use weak spleen staining alone to diagnose assay failure (HPA: tissue IHC; general IHC practice). |
| The slide stains, but the result remains hard to interpret. | An Approved IHC rating coexists with low consistency between staining and RNA expression; the supplied antibody record does not show Enhanced IHC validation (HPA: reliability, antibodies). | Record compartment, cell identity and control behavior, then report the staining as an observed pattern with the HPA evidence limitation (general IHC practice; HPA: tissue IHC reliability). |
Experiment evidence
IHC & IF images showing NKX3-2 staining
A07429 · IHCImmunohistochemistry of BAPX1 in mouse brain tissue with BAPX1 antibody at 5 μg/mL.
A07429 · IFImmunofluorescence of BAPX1 in mouse brain tissue with BAPX1 antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000109705-NKX3-2/tissue/cerebral+cortex#imid_7125528
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000109705-NKX3-2/tissue/colon#imid_7127910
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000109705-NKX3-2/tissue/liver#imid_7127903
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000109705-NKX3-2/tissue/kidney#imid_7127904
HPA · ICC-IF HAP1Human Protein Atlas immunofluorescence, HAP1, antibody HPA027564; green = NKX3-2, blue = nucleus, red = microtubules.
HPA · ICC-IF HAP1Human Protein Atlas immunofluorescence, HAP1, antibody HPA027564; green = NKX3-2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for NKX3-2 IHC & IF
🧪Run appendix first: its glandular cells should show nuclear staining (HPA: Medium in appendix glandular cells; UniProt P78367: nucleus). HPA detects NKX3-2 in all 45 scored tissues, so there is no HPA negative tissue; use no-primary and isotype controls, and expect any internal cells without target signal to lack nuclear staining (HPA: no negative tissue; UniProt P78367: nucleus).
Positive control tissue: Adipose tissue (Adipocytes, HPA Medium)
Negative control tissue: None in HPA: NKX3-2 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 NKX3-2 in HAP1, THP-1, U2OS, NIH 3T3, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and a control immunoglobulin matched to the primary antibody’s host species and clonality. If available, use NKX3-2 knockout material as a biological negative; block endogenous peroxidase and check for background in appendix inflammatory cells before interpreting chromogenic signal (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected A07429 mouse-brain IHC caption does not state a fixative (A07429 caption: fixative unreported). Antigen retrieval dependence is unreported, and the evidence does not establish whether frozen sections or IF/ICC are easier for NKX3-2. In appendix, endogenous peroxidase in inflammatory cells can produce chromogenic background, so assess it with the no-primary control (standard IHC practice).
HPA tissue IHC evidence for NKX3-2
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 → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Adipocytes | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: NKX3-2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced NKX3-2 IHC Tips
Troubleshoot chromogenic NKX3-2 IHC in paraffin sections by checking nuclear staining, tissue controls and workflow variables (UniProt P78367; HPA tissue IHC).
What should I change if nuclear staining is weak after antigen retrieval?
Start with Tris-EDTA at pH 9.0 for heat-induced retrieval at 95–98 °C for 20 min (page retrieval method). If nuclear staining is weak, compare a modestly longer exposure on serial sections while keeping the antibody concentration and detection conditions constant (standard IHC practice). Assess tissue integrity as well as signal, because excessive heat can damage section morphology and make nuclear scoring unreliable (standard IHC practice). Use the same retrieval and cooling conditions for test and control sections; NKX3-2 is expected in nuclei, so a stronger diffuse cytoplasmic signal alone does not establish improved retrieval (UniProt P78367 localisation; standard IHC practice).
Could fixation explain variable NKX3-2 staining between paraffin blocks?
Target-specific fixation sensitivity for NKX3-2 is unknown from the supplied evidence (selected A07429 tissue-IHC caption; HPA tissue IHC). The selected mouse brain caption reports staining at 5 µg/mL but does not state the fixative, so it cannot establish an optimal fixation condition (selected A07429 tissue-IHC caption). Compare blocks with documented fixation histories using identical retrieval, antibody concentration and detection settings, then assess nuclear signal alongside preserved morphology (standard IHC practice; UniProt P78367 localisation). Include a consistently processed reference section in each run and record fixation duration when available; differences across blocks warrant a controlled comparison before biological interpretation (standard IHC practice).
Where should convincing NKX3-2 staining appear in tissue sections?
Score convincing NKX3-2 signal within nuclei, ideally resolved against the counterstain (UniProt P78367 localisation; HPA tissue IHC). The HPA describes nuclear staining across tissues and an approved nucleoplasmic location in cell imaging, although its tissue staining has low consistency with RNA expression data (HPA tissue IHC; HPA subcellular). NKX3-2 has no annotated transmembrane segment or signal peptide, so a dominant membrane pattern needs independent validation (UniProt P78367 topology and processing). Compare nuclear and cytoplasmic signal in the same cells at matched exposure and detection settings, and review cell identity with the tissue morphology before calling a section positive (standard IHC practice).
How should I investigate an unexpected staining pattern when the epitope is unclear?
NKX3-2 is represented here by one 1–333 chain, with no listed isoforms, glycosylation sites or modified residues (UniProt P78367 processing, isoforms and PTMs). Those annotations do not identify the antibody epitope or prove that fixation and retrieval preserve its accessibility (UniProt P78367 record; standard IHC practice). Check the catalog antibody’s immunogen or epitope documentation, then compare staining with an independently validated antibody targeting another region if one is available (standard IHC practice). Keep retrieval and chromogenic detection matched during that comparison, and require concordant nuclear localisation and tissue morphology before attributing discrepant staining to an NKX3-2 variant (UniProt P78367 localisation; standard IHC practice).
How can IF help check an ambiguous chromogenic NKX3-2 result?
On the separate IF/ICC workflow, pair NKX3-2 with a marker for the cell population being examined and check whether signal occupies the expected nuclei (UniProt P78367 localisation; standard IF practice). Choose fluorophores after inspecting unstained tissue for autofluorescence, and reserve a spectrally distinct channel for the nuclear counterstain (standard IF practice). Because NKX3-2 is nuclear and has no transmembrane segment, optimise permeabilisation for access to the nucleus rather than assuming a membrane-facing epitope (UniProt P78367 localisation and topology; standard IF practice). Include single-label and secondary-only controls to distinguish bleed-through or nonspecific fluorescence from a biological difference with the chromogenic section (standard IF practice).
How do I separate weak nuclear staining from chromogenic background?
Inspect a no-primary control for nonspecific detection and endogenous enzyme signal before increasing the catalog antibody concentration (standard IHC practice). Apply a peroxidase block when using horseradish-peroxidase detection, and evaluate DAB deposition as a general chromogenic workflow step rather than NKX3-2-specific evidence (standard IHC practice). Compare sections at the same development time, checking whether brown signal is confined to nuclei or follows folds, edges or damaged tissue (UniProt P78367 localisation; standard IHC practice). The selected mouse brain image reports 5 µg/mL, but its caption does not establish that concentration as optimal for other paraffin sections or fixation conditions (selected A07429 tissue-IHC caption).
What should I measure when comparing NKX3-2 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define eligible cells by morphology, then report the percentage of nuclei positive for NKX3-2 and an H-score if staining intensity is reliably separable (UniProt P78367 localisation; standard IHC practice). For sparse populations, positive nuclei per mm² of viable tissue can supplement the percentage (standard IHC practice). Normalise counts to the number of eligible nuclei or sampled viable area, and apply the same threshold, regions and exclusion rules to every section (standard IHC practice). Record retrieval, detection and batch conditions with the score; HPA reports low consistency between antibody staining and RNA expression, so staining intensity alone should not be treated as a direct expression measurement (HPA tissue IHC; standard IHC practice).
When should I doubt an apparent NKX3-2-positive region?
Treat predominantly cytoplasmic or membrane staining cautiously because NKX3-2 is annotated as nuclear and lacks a transmembrane segment (UniProt P78367 localisation and topology). Check that positive nuclei belong to the cell population under study, using section morphology and an appropriate cell marker when cell identity is uncertain (standard IHC practice). Exclude edge deposits, folds and necrotic areas from scoring, and use a no-primary control to assess nonspecific detection or endogenous peroxidase signal (standard IHC practice). HPA reports nuclear staining across tissues but low consistency with RNA expression, so an unexpected positive region needs corroboration through controls or an independent method before a biological claim (HPA tissue IHC; standard IHC practice).
Boster reagents
Best NKX3-2 / Homeobox protein Nkx-3.2 IHC Antibodies
A07429 has mouse brain tissue IHC and IF images (catalog image captions); its listed reactivity covers human, mouse and rat (catalog reactivity).
Real IHC data
Anti-BAPX1 NKX3-2 Antibody
Cat # A07429
A07429 has an IHC image from mouse brain tissue at 5 μg/mL (catalog IHC image caption). Its IF image is also from mouse brain tissue, at 20 μg/mL (catalog IF image caption).
Which to pick: Choose A07429 for paraffin-section IHC: IHC-P is listed, and its own IHC image shows mouse brain tissue (catalog applications; catalog IHC image caption); the fixative is unreported (catalog IHC image caption). Choose A07429 for tissue IF based on its mouse brain IF image; ICC validation is unreported (catalog IF image caption; catalog applications). For work across species, A07429 lists human, mouse and rat reactivity, though the supplied IHC and IF images show mouse tissue only (catalog reactivity; catalog image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P78367 (NKX32_HUMAN, Homeobox protein Nkx-3.2).
- Human Protein Atlas. NKX3-2 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. NKX3-2 subcellular location (ICC-IF): Localized to the nucleoplasm..
- Human Protein Atlas. NKX3-2 antibody validation summary (1 antibodies).
- Role of the homeodomain transcription factor Bapx1 in mouse distal stomach development. Gastroenterology 2009 — PMC2955323.
- Integration of Single-Cell RNA Sequencing and Bulk RNA Sequencing to Identify an Immunogenic Cell Death-Related 5-Gene Prognostic Signature in Hepatocellular Carcinoma. Journal of hepatocellular carcinoma 2024 — PMC11104445.
- PubMed PMID:9426254 — UniProt-cited evidence.
- PubMed PMID:9344671 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for NKX3-2 (Homeobox protein Nkx-3.2). Expected localisation Nuclear staining in tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: A07429 at 5 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC 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 A07429); 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-NKX3-2, 5 μg/mL (datasheet A07429); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Low consistency between staining and RNA expression (HPA tissue IHC); Isoform / epitope: No isoforms or processing annotated; epitope effects unknown (UniProt); Regulation: No stimulus-linked regulation annotated (UniProt). Evidence: UniProt P78367, HPA tissue IHC · Approved, HPA ICC-IF · nucleoplasm., Datasheet A07429, PMC11104445. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/NKX3-2/immunohistochemistry-ihc-guide.