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KAT5 / Histone acetyltransferase KAT5 · IHC design guide
Design Immunohistochemistry for KAT5
Plan KAT5 staining in paraffin sections using the nuclear tissue pattern and high-staining cell types reported by HPA (HPA tissue IHC). This guide covers fixation consistency, antigen retrieval, the catalog antibody’s 1:100–1:300 IHC dilution range, and localisation changes reported for KAT5 (standard IHC practice; datasheet: 1:100–1:300; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
KAT5 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 in most tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in cells across most tissues (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Caudate+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 | EDN1 stimulation can shift KAT5 to the perinuclear region (UniProt) | |
| Regulation | PDCD5 stabilizes KAT5 (UniProt) | |
| Isoform / epitope | 4 isoforms; check antibody epitope coverage (UniProt) |
Section 1
Recommended KAT5 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by published KAT5 staining procedures for heart tissue (PMC10985082) and tissue sections (PMC13079337).
| Sample | Paraffin-embedded human brain tissue; fixative not specified (datasheet A30543) |
| Fixation | Image fixative and duration unreported (datasheet A30543); 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-KAT5, 1:100 - 1:300 (datasheet A30543) |
| 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 | KAT5-positive staining in neuronal cells of caudate (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 at 95–98 °C for 20 min (page antigen retrieval); compare citrate retrieval when optimizing against these published methods (PMC10985082; PMC13079337).
Section 2
What Is the Expected KAT5 Staining Pattern?
KAT5 should stain mainly nuclei in most tissues (HPA tissue IHC: nuclear expression in most tissues; HPA ICC-IF: supported nucleoplasm). Strong examples include neuronal cells in caudate and glandular cells in colon (HPA tissue IHC: High). KAT5 has no transmembrane segment (UniProt Q92993: topology). HPA rates its tissue IHC pattern Approved, with medium consistency between staining and RNA expression (HPA tissue IHC: reliability).
| Distinct nuclear chromogen in neuronal or glandular cells. | This fits the expected compartment and documented strong examples (HPA tissue IHC: nuclear expression; High in caudate neuronal cells and colon glandular cells). Compare the positive nuclei with neighboring tissue and the counterstain; intensity alone does not establish antibody specificity (general IHC interpretation). |
| Predominantly membranous or widespread cytoplasmic staining with little nuclear signal. | Treat this as discordant with the usual tissue pattern (HPA tissue IHC: nuclear expression in most tissues). KAT5 lacks a transmembrane segment (UniProt Q92993: topology). Some cytoplasmic localization is reported, so isolated extranuclear signal is not automatically false (UniProt Q92993: subcellular location). |
| Strong staining in a cell population expected to be weak in the chosen tissue. | Possible cross-reactivity or endogenous detection activity should be checked with appropriate controls (general IHC interpretation). HPA reports Low staining in pancreatic exocrine glandular cells and splenic red-pulp cells; Low does not mean absent (HPA tissue IHC: Low). Do not reject a slide solely because these cells stain faintly. |
| Broad, diffuse chromogen obscures nuclei and tissue boundaries. | The pattern cannot be scored confidently against the predominantly nuclear reference (HPA tissue IHC: nuclear expression in most tissues). Background can arise from detection chemistry, inadequate blocking, or excess antibody concentration (general IHC practice); a reagent control helps identify detection-derived signal (general IHC practice). |
| No nuclear signal in a documented strong-positive tissue. | First suspect an assay or specimen problem, rather than calling KAT5 absent (HPA tissue IHC: High in cerebellar Purkinje cells and cervical glandular cells). Check tissue preservation, retrieval, antibody and detection steps with a concurrent positive control (general IHC practice). HPA's Approved rating is not a guarantee for every specimen (HPA tissue IHC: reliability). |
💡Expected KAT5 appearanceCall a result consistent when cell nuclei show clear chromogen, especially in HPA High neuronal or glandular populations; predominantly membranous staining or diffuse color that obscures nuclei is discordant (HPA tissue IHC: nuclear expression; High in caudate neuronal cells and colon glandular cells; UniProt Q92993: topology; general IHC interpretation).
| Tissue and cell selection | Choose a documented High population for the positive control, such as cerebellar Purkinje cells or duodenal glandular cells (HPA tissue IHC: High). Pancreatic exocrine glandular cells are Low and are a weaker sensitivity check, not an established negative control (HPA tissue IHC: Low; negative list empty). |
| Compartment and antibody evidence | The tissue reference is nuclear, and HPA016953 is IHC Approved (HPA tissue IHC: profile; HPA antibodies: HPA016953). This supports a nuclear interpretation, while the tissue reliability statement notes only medium staining–RNA consistency (HPA tissue IHC: reliability). |
| KAT5 location and processing | A soluble nuclear pattern fits the absence of a transmembrane segment, signal peptide, and propeptide; the annotated chain spans residues 1–513 (UniProt Q92993: topology and processing). These annotations give no basis for expecting a cell-surface or secreted staining pattern (UniProt Q92993: topology and processing). |
| Isoforms and epitope uncertainty | UniProt lists four KAT5 isoforms, but the supplied evidence gives no antibody epitope or isoform coverage (UniProt Q92993: isoforms; HPA antibodies: validation status only). Do not assign a tissue staining difference to a particular isoform from this IHC result alone (general IHC interpretation). |
| IF/ICC Q: where should fluorescence appear? | Mainly in the nucleoplasm (HPA ICC-IF: supported main location). Vesicle and cytosol signals are listed as uncertain, so interpret them cautiously (HPA ICC-IF: additional locations). These cell-image observations are context for localization, not an IF/ICC protocol or a substitute for the tissue IHC reference (HPA ICC-IF; HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known High tissue is completely blank. | The stain may have failed at retrieval, antibody incubation, or detection (general IHC practice); a blank slide does not overturn HPA's High observation (HPA tissue IHC: High in colon glandular cells). | Run a concurrent documented High tissue and check each assay step against the catalog antibody's IHC-P instructions (HPA tissue IHC: High; general IHC practice). |
| Signal is weak but clearly nuclear in a Low tissue. | That may match the reference rather than indicate failure (HPA tissue IHC: Low in prostate glandular cells; nuclear expression in most tissues). | Compare with a documented High tissue in the same run before adjusting conditions (HPA tissue IHC: High in cervical glandular cells; general IHC practice). |
| Chromogen covers nuclei and surrounding tissue uniformly. | Excess primary antibody, incomplete blocking, or detection background may reduce contrast (general IHC practice). | Check a reagent control and optimize blocking, primary concentration, and detection conditions according to the assay instructions (general IHC practice). |
| A strong membrane outline dominates the slide. | That location conflicts with the usual nuclear tissue pattern and KAT5 topology (HPA tissue IHC: nuclear expression; UniProt Q92993: no transmembrane segment). | Check control staining and review whether the outline follows a tissue edge or detection artefact before scoring cells (general IHC practice). |
| Cytoplasmic staining accompanies a convincing nuclear signal. | KAT5 has annotated cytoplasmic locations, although tissue IHC is mainly nuclear (UniProt Q92993: subcellular location; HPA tissue IHC: profile). | Record nuclear and cytoplasmic staining separately; compare the extranuclear component with controls rather than treating every cytoplasmic pixel as a positive cell (general IHC interpretation). |
| A control slide stains, but the study specimen does not. | Biological variation or a specimen-specific assay issue remains possible; HPA reports Low tissue specificity at the RNA level and medium staining–RNA consistency (HPA tissue IHC: RNA specificity and reliability). | Review cell identity, specimen quality, and run controls, then report the observed result without claiming KAT5 absence from one slide (general IHC practice). |
Experiment evidence
IHC & IF images showing KAT5 staining
A30543 · IHCImmunohistochemistry analysis of paraffin-embedded human brain tissue, using TIP60 Antibody. The picture on the right is blocked with the sy
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000172977-KAT5/tissue/cerebral+cortex#imid_4468092
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000172977-KAT5/tissue/colon#imid_4468018
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000172977-KAT5/tissue/liver#imid_4468019
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000172977-KAT5/tissue/kidney#imid_4468020
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA016953; green = KAT5, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA016953; green = KAT5, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for KAT5 IHC & IF
🧪Run cerebral cortex first and look for staining in neuronal cells, which HPA scores High (HPA: cerebral cortex, neuronal cells). HPA detects KAT5 in all 45 scored tissues, so there is no validated negative tissue; use no-primary and isotype controls, and treat any unstained neighboring cells as background comparators rather than confirmed KAT5-negative cells (HPA: no negative tissue rows; detected in all 45 tissues).
Positive control tissue: Caudate (Neuronal cells, HPA High)
Negative control tissue: None in HPA: KAT5 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 KAT5 in A-431, U-251MG, U2OS, MCF-7, RT-4, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and an isotype control matched to the primary antibody’s host species and clonality (standard IHC practice). For a biological specificity check, use KAT5-knockout material if available or a peptide-blocking control, as shown in the selected brain IHC caption (selected SKU A30543 caption: peptide block). Quench endogenous peroxidase in chromogenic IHC and assess tissue pigment against the control slides (standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected paraffin-section brain caption does not state its fixative (selected SKU A30543 caption: fixative not stated). Retrieval dependence and whether frozen sections or IF are easier are unreported in the supplied application evidence. For brain IF, check autofluorescence before assigning a signal to KAT5; nucleoplasmic staining is the supported ICC-IF location, while vesicular and cytosolic locations are uncertain (standard IF practice; HPA: subcellular localization).
HPA tissue IHC evidence for KAT5
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium 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 |
|---|---|---|---|---|
| Caudate | Neuronal cells | High | Protein (IHC) | HPA → |
| Cerebellum | Purkinje cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Cervix | Glandular cells | High | Protein (IHC) | HPA → |
| Colon | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: KAT5 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced KAT5 IHC Tips
Use compartment-aware controls and matched processing to troubleshoot KAT5 staining in paraffin sections (UniProt Q92993; HPA tissue IHC).
How should I adjust retrieval when nuclear KAT5 staining is weak?
Start with Tris-EDTA pH 9.0 heat-induced retrieval at 95–98 °C for 20 min (page retrieval setting: nuclear antigen). Cool sections in the retrieval solution, then wash in PBS before applying the IHC-validated antibody (standard IHC practice). If nuclear staining remains weak, compare a longer retrieval time on matched sections while keeping antibody incubation and detection constant (standard IHC practice). Score nuclear signal alongside tissue preservation and background, because excessive heating can compromise morphology (standard IHC practice). Use the same retrieval conditions for comparison and control sections so differences reflect staining rather than processing (standard IHC practice).
Could fixation explain variable KAT5 staining between paraffin specimens?
KAT5-specific fixation sensitivity is unknown from the supplied evidence; the catalog brain image describes paraffin-embedded tissue but does not state its fixative (A30543 caption). Record fixative, fixation duration, and processing history for every specimen before comparing nuclear intensity (standard IHC practice). For newly collected tissue, a controlled pilot using 10% neutral buffered formalin and a documented fixation interval can establish a reproducible local baseline (standard IHC practice). Process pilot sections together and apply the same pH 9.0 retrieval and detection conditions (page retrieval setting; standard IHC practice). Treat any fixation effect observed in that pilot as assay-specific until independently confirmed (standard IHC practice).
Is cytoplasmic or punctate KAT5 staining biologically plausible?
Expect predominantly nuclear staining in tissue, consistent with nuclear expression in most tissues and supported nucleoplasmic localisation in cell imaging (HPA tissue IHC; HPA subcellular). KAT5 also has reported cytoplasmic, perinuclear, nucleolar, chromosome, kinetochore, and spindle-pole locations under particular conditions (UniProt Q92993 subcellular). EDN1 stimulation is linked to perinuclear export, while UV irradiation is linked to punctate nuclear bodies; neither condition can be inferred from staining alone (UniProt Q92993 subcellular). Compare the pattern with a nuclear counterstain and assess whether puncta lie within intact nuclei (standard IHC practice). Investigate diffuse cytoplasmic chromogen with matched controls before assigning it to KAT5 (standard IHC practice).
How can isoforms or epitope masking affect KAT5 IHC?
KAT5 has 4 annotated isoforms, so check the antibody's mapped immunogen before assuming that every isoform is detected (UniProt Q92993 isoforms; standard IHC practice). Its Tudor-knot spans residues 8–65 and its MYST-type HAT domain spans 227–504 (UniProt Q92993 domains). Several modified residues occur near the N terminus, including acetyllysines at 52, 104, and 120; the supplied evidence does not establish their effect on antibody binding (UniProt Q92993 modified residues). A30543's paraffin brain image includes a peptide-blocked comparison, which supports evaluating that antibody's signal specificity in its displayed setting (A30543 caption). Confirm the antibody's epitope and compare matched retrieval conditions before attributing staining differences to isoforms (standard IHC practice).
How should I assess KAT5 in a companion multiplex IF experiment?
On a separate IF/ICC assay, pair KAT5 with a marker for the expected cell population, such as a neuronal-cell marker when examining the brain context shown for the catalog antibody (A30543 caption; standard IF practice). Use a nuclear counterstain to test overlap with the expected nucleoplasmic signal (HPA subcellular; standard IF practice). Choose spectrally separated fluorophores and consider a far-red channel if tissue autofluorescence obscures shorter wavelengths (standard IF practice). KAT5 has no annotated transmembrane segment and is mainly nucleoplasmic, so a trial with 0.1% Triton X-100 for 5 min can test access to an intracellular epitope (UniProt Q92993 topology; HPA subcellular; standard IF practice). Include single-label and no-primary controls to assess bleed-through and background (standard IF practice).
What should I check when chromogenic KAT5 staining is diffuse?
First compare the stained section with a no-primary control and inspect whether color tracks tissue edges, folds, or damaged areas (standard IHC practice). For peroxidase-based detection, test a 3% hydrogen peroxide block for 10 min as a general workflow starting point, then rinse before antibody incubation (standard IHC practice). Adjust blocking, antibody concentration, and wash duration one variable at a time while retaining matched positive tissue (standard IHC practice). The A30543 brain image includes a synthesized-peptide blocked comparison, but that control does not establish the cause of background in another specimen (A30543 caption). Prioritize nuclear signal over diffuse chromogen when reviewing KAT5 (HPA tissue IHC; standard IHC practice).
How should I quantify KAT5 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and nuclear positivity threshold before scoring, using the same counterstain and imaging settings across sections (standard IHC practice). Report an H-score from percentage of cells at intensity grades 0–3, or report the percentage of positive nuclei when intensity grading is unreliable (standard IHC practice). For spatial analyses, count positive nuclei per mm² of viable tissue and also report total nuclei or area assessed (standard IHC practice). Normalize comparisons to eligible cells within the same tissue compartment and exclude folds, necrosis, and section edges by a prespecified rule (standard IHC practice). Keep cytoplasmic staining separate from the primary nuclear score because tissue expression is predominantly nuclear (HPA tissue IHC).
When is an apparent KAT5-positive cell likely an artefact?
A convincing result shows staining in intact nuclei of the assessed cell population, consistent with the predominant tissue pattern (HPA tissue IHC; standard IHC practice). High nuclear staining is reported in neuronal cells of caudate and cerebral cortex, while low staining is reported in exocrine pancreatic glandular cells; these are reference observations, not universal thresholds (HPA tissue IHC). Treat isolated edge staining, necrotic deposits, and signal in a no-primary control as potential technical artefacts (standard IHC practice). For peroxidase detection, check endogenous enzyme activity before interpreting diffuse chromogen as KAT5 (standard IHC practice). The HPA tissue profile has Approved reliability with medium staining-to-RNA consistency, so resolve discordant findings with independent controls (HPA tissue IHC).
Boster reagents
Best KAT5 / Histone acetyltransferase KAT5 IHC Antibodies
A30543 has a real IHC image from paraffin-embedded human brain (IHC image caption); the catalog also lists IF/ICC applications and Human, Mouse, and Rat reactivity (catalog: applications, reactivity).
Real IHC data
Anti-TIP60 KAT5 Antibody
Cat # A30543
A30543 has IHC image data from paraffin-embedded human brain, including a peptide-blocked comparison (IHC image caption). A30543 lists IF/ICC applications and Human, Mouse, and Rat reactivity (catalog: applications, reactivity); no IF image is supplied (catalog: IF images).
Which to pick: Choose A30543 for tissue IHC when working with paraffin sections, as shown in human brain (IHC image caption); the fixative is unreported (IHC image caption). For IF/ICC, A30543 is the listed option (catalog: applications), though no IF image is supplied (catalog: IF images). It is also the listed cross-species option for Human, Mouse, and Rat (catalog: reactivity); its antibody is polyclonal (catalog: dilution details).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q92993 (KAT5_HUMAN, Histone acetyltransferase KAT5).
- Human Protein Atlas. KAT5 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. KAT5 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to vesicles and cytosol..
- Human Protein Atlas. KAT5 antibody validation summary (2 antibodies).
- STUB1 is acetylated by KAT5 and alleviates myocardial ischemia-reperfusion injury through LATS2-YAP-β-catenin axis. Communications biology 2024 — PMC10985082.
- KAT5 Negatively regulates the proliferation of prostate cancer LNCaP cells via the caspase 3-dependent apoptosis pathway. Animal cells and systems 2019 — PMC6711033.
- Integrative genomic analysis identifies key target genes and candidate drugs for spinal stenosis. Frontiers in molecular neuroscience 2026 — PMC13079337.
- Essential Regulation of Spermatogonial Stem Cell Fate Decisions and Male Fertility by APBB1 via Interaction with KAT5 and GDF15 in Humans and Mice. Research (Washington, D.C.) 2025 — PMC11948500.
- PubMed PMID:8607265 — UniProt-cited evidence.
- PubMed PMID:11416127 — UniProt-cited evidence.
- PubMed PMID:12801643 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for KAT5 (Histone acetyltransferase KAT5). Expected localisation Nuclear in most tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: A30543 at 1:100 - 1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Caudate (Neuronal cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human brain tissue; fixative not specified (datasheet A30543); 2. Fixation: Image fixative and duration unreported (datasheet A30543); 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-KAT5, 1:100 - 1:300 (datasheet A30543); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: EDN1 stimulation can shift KAT5 to the perinuclear region (UniProt); Isoform / epitope: 4 isoforms; check antibody epitope coverage (UniProt); Regulation: PDCD5 stabilizes KAT5 (UniProt). Evidence: UniProt Q92993, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to…, Datasheet A30543, PMC10985082, PMC13079337. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/KAT5/immunohistochemistry-ihc-guide.