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STK26 / Serine/threonine-protein kinase 26 · IHC design guide
Design Immunohistochemistry for STK26
Plan STK26 paraffin IHC around cytoplasmic staining in selected tissues (HPA tissue IHC). Use the IHC-validated antibody’s dilution and compare staining with controls because tissue staining has low consistency with RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
STK26 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 tissue staining (HPA tissue IHC); Golgi location (UniProt) | |
| Staining pattern | Cytoplasmic staining in glandular cells and myocytes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A09552-2) | |
| Positive control | Gallbladder+4 more · see all | |
| 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 | Staining has low consistency with RNA expression (HPA tissue IHC) | |
| Regulation | Serum stimulation shifts Golgi signal to puncta (UniProt) | |
| Isoform / epitope | 3 isoforms; epitope coverage needs checking (UniProt) |
Section 1
Recommended STK26 IHC & IF Protocols
The catalog antibody uses EDTA pH 8.0 heat retrieval (datasheet A09552-2). One published choriocarcinoma IHC protocol provides a comparison (PMC7683511).
| Sample | Paraffin-embedded human ovarican cancer tissue; fixative not specified (datasheet A09552-2) |
| Fixation | Image fixative and duration unreported (datasheet A09552-2); 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 A09552-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A09552-2) |
| Primary antibody | Rabbit anti-STK26, 2-5 μg/ml (datasheet A09552-2) |
| Primary incubation | Overnight at 4 °C (datasheet A09552-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A09552-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | STK26-positive staining in glandular cells of gallbladder (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in a few tissues. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 retrieval for the catalog antibody (datasheet A09552-2); the published protocol used pH 7.5 retrieval (PMC7683511).
Section 2
What Is the Expected STK26 Staining Pattern?
STK26 is a cytoplasmic, Golgi-associated kinase without a transmembrane segment (UniProt Q9P289 topology and subcellular location). In paraffin-section IHC, expect cytoplasmic staining in gallbladder and small-intestinal glandular cells and skeletal-muscle myocytes (HPA: High). Treat these as reference patterns, not universal positives: HPA rates the tissue IHC antibody Approved but reports low agreement between staining and RNA expression, pending external verification (HPA: tissue IHC reliability).
| Cytoplasmic staining in gallbladder or small-intestinal glandular cells, or skeletal-muscle myocytes. | This matches the reported High cell-specific IHC pattern (HPA: tissue IHC). Assess the named cells against neighboring structures and background on the same section. The observed compartment also agrees with the cytoplasmic location (UniProt Q9P289 subcellular location). |
| Strong nuclear staining dominates the IHC slide, with little cytoplasmic signal. | This departs from the reported tissue IHC profile of cytoplasmic expression (HPA: tissue IHC). Check morphology and staining controls before calling it STK26. HPA ICC-IF lists nucleoplasm as an uncertain main location, so that separate observation does not by itself validate a nuclear IHC pattern (HPA: subcellular ICC-IF). |
| Prominent staining appears in cells reported as undetected, such as bone-marrow hematopoietic cells or adipocytes. | Consider off-target binding or endogenous detection activity, then compare controls and cell identity; one unexpected section cannot establish cross-reactivity. HPA reports these cells as Not detected by IHC, yet lists bone marrow among RNA-enhanced tissues, a reminder that the protein and RNA observations disagree (HPA: tissue IHC and RNA specificity). |
| Diffuse color covers multiple compartments or obscures cell boundaries. | Treat an indistinct, section-wide signal as background until controls and morphology support a cellular pattern. The useful reference is cytoplasmic staining in a few tissues (HPA: tissue IHC), with cytoplasm and Golgi localization described independently (UniProt Q9P289 subcellular location). General IHC practice is to inspect detection-only controls and background before scoring. |
| No interpretable signal appears in gallbladder glandular cells or skeletal-muscle myocytes. | A blank known-positive comparator suggests a failed or insensitive run, but the HPA reference is an observed High pattern rather than a guarantee for every specimen (HPA: tissue IHC). Review tissue preservation, retrieval, antibody application, and detection as general IHC checks; avoid scoring other samples as truly negative until the comparator works. |
💡Expected STK26 appearanceCall a positive IHC result when distinct cytoplasmic signal is High in gallbladder or small-intestinal glandular cells or skeletal-muscle myocytes (HPA: tissue IHC), while widespread featureless color or dominant nuclear-only staining warrants investigation against the cytoplasmic reference (HPA: tissue IHC; UniProt Q9P289 subcellular location).
| Cell type and reference tissue | Choose the named High IHC cell populations when judging whether a run can reveal STK26; adrenal and colon glandular cells, cerebellar granular-layer cells, and lung macrophages are reported Medium (HPA: tissue IHC). A negative result in a different cell population carries less weight. |
| Cellular compartment and cell state | Cytoplasm and Golgi are annotated locations (UniProt Q9P289 subcellular location). UniProt describes Golgi colocalization with RIPOR1 in serum-starved cells and relocation to cytoplasmic puncta after serum stimulation (UniProt Q9P289, PubMed:27807006). This cell-state observation is not an IHC tissue scoring rule. |
| Antibody evidence and RNA discordance | The listed HPA antibody, HPA059921, is IHC Approved, while the tissue profile has low agreement with RNA and awaits external verification (HPA: antibody validation and tissue IHC reliability). Bone marrow illustrates the limit: RNA is tissue enhanced, but hematopoietic-cell IHC is Not detected (HPA: tissue IHC and RNA specificity). |
| IF/ICC Q&A: should nuclear fluorescence be expected? | HPA reports nucleoplasm as an uncertain main ICC-IF location, with supported Golgi and cytosol locations; its listed antibody is ICC Uncertain (HPA: subcellular ICC-IF and antibody validation). Interpret nuclear fluorescence with that uncertainty and assess localization on the separate IF/ICC guide page. |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive comparator is blank. | General IHC possibilities include insufficient retrieval, missed primary antibody, or failed detection; none is a demonstrated STK26-specific fixation effect. | Repeat with a named High cell population and working assay controls (HPA: tissue IHC); review retrieval and detection records as general IHC checks before interpreting study negatives. |
| Nuclear signal exceeds cytoplasmic signal. | Dominant nuclear IHC conflicts with the reported cytoplasmic tissue pattern (HPA: tissue IHC), although HPA separately marks nucleoplasmic ICC-IF localization uncertain (HPA: subcellular ICC-IF). | Verify cell boundaries and counterstain; compare an appropriate negative control and a positive tissue before assigning nuclear STK26. Keep the IHC and ICC-IF observations distinct. |
| A reported negative cell population stains strongly. | Possible nonspecific antibody binding or endogenous detection activity; HPA lists adipocytes and bone-marrow hematopoietic cells as Not detected by IHC (HPA: tissue IHC). | Confirm the cell type, inspect primary-omission and detection controls, and compare a named positive population. Treat a disagreement as unresolved until the signal is independently supported. |
| Diffuse chromogen makes localization unreadable. | General IHC causes include excess detection background or inadequate blocking; a diffuse field cannot be matched confidently to HPA's cytoplasmic profile (HPA: tissue IHC). | Inspect a detection-only control, review blocking and reagent exposure, and score only cells with distinguishable morphology and compartmental signal. |
| Only weak signal appears in a candidate tissue. | Signal may reflect the sampled cell population: HPA reports Medium in lung macrophages and Not detected in heart-muscle cardiomyocytes (HPA: tissue IHC). | Identify the stained cells before comparing intensity; include a reported High comparator and use the same scoring criteria across sections (HPA: tissue IHC). |
| RNA data suggest expression where IHC is negative. | HPA reports bone marrow and epididymis as RNA-enhanced tissues, yet the specified hematopoietic and epididymal glandular cells are Not detected by IHC; overall RNA–staining agreement is low (HPA: tissue IHC and RNA specificity). | Report the protein-level observation and the discordance separately. Check an IHC-positive comparator and seek independent validation before calling the negative result a technical failure. |
Experiment evidence
IHC & IF images showing STK26 staining
A09552-2 · IHCIHC analysis of MST4/STK26 using anti-MST4/STK26 antibody (A09552-2). MST4/STK26 was detected in a paraffin-embedded section of human ovaric
A09552-2 · IHCIHC analysis of MST4/STK26 using anti-MST4/STK26 antibody (A09552-2). MST4/STK26 was detected in a paraffin-embedded section of human colon
M09552 · IHCIHC analysis of MST4/STK26 using anti-MST4/STK26 antibody (M09552). MST4/STK26 was detected in a paraffin-embedded section of human colon ca
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000134602-STK26/tissue/cerebral+cortex#imid_16463083
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000134602-STK26/tissue/colon#imid_16462001
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000134602-STK26/tissue/liver#imid_16461986
HPA · GallbladderHuman Protein Atlas IHC, Gallbladder. Source: https://www.proteinatlas.org/ENSG00000134602-STK26/tissue/gallbladder#imid_16461978
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA059921; green = STK26, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA059921; green = STK26, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for STK26 IHC & IF
🧪Run gallbladder first and expect staining in its glandular cells (HPA: High in gallbladder glandular cells). Use adipose tissue as the negative tissue, scoring adipocytes (HPA: Not detected in adipocytes); on the gallbladder slide, compare glandular staining with non-glandular cells as an internal background reference, without assuming those cells lack STK26.
Positive control tissue: Gallbladder (Glandular cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show STK26 in A-431, HEK293, U2OS, with annotated localisation: Nucleoplasm (uncertain) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only section; a concentration-matched rabbit IgG control matched to the primary antibody’s clonality; and STK26-knockout material as a biological negative (caption: rabbit primary antibody; standard IHC controls). For gallbladder DAB staining, quench endogenous peroxidase and distinguish any bile pigment from cell-associated signal (caption: HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A paraffin-section example uses heat retrieval in EDTA at pH 8.0, but one example does not establish that retrieval is required (selected-SKU IHC caption). Its fixative is unreported, and the supplied evidence reports no STK26-specific fixation window or fixation effect (selected-SKU IHC caption). The evidence does not establish that frozen sections or IF/ICC are easier; when scoring gallbladder DAB sections, assess bile pigment separately from staining (selected-SKU IHC caption; standard IHC practice).
HPA tissue IHC evidence for STK26
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low consistency between antibody staining and RNA expression data. Pending external verification.). 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 |
|---|---|---|---|---|
| Gallbladder | Glandular cells | High | Protein (IHC) | HPA → |
| Skeletal muscle | Myocytes | High | Protein (IHC) | HPA → |
| Small intestine | Glandular cells | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Endometrium | Cells in endometrial stroma | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced STK26 IHC Tips
Troubleshoot STK26 staining in paraffin sections by checking retrieval, cell type, compartment and controls before comparing staining intensity (datasheet A09552-2; HPA tissue IHC; UniProt Q9P289).
Which retrieval condition should I try first for weak STK26 staining?
Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A09552-2). The selected antibody's tissue image used this condition, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A09552-2). If staining remains weak, compare retrieval duration on adjacent sections while holding antibody concentration and detection constant (standard IHC practice). Use a section with a documented positive cell population, such as gallbladder glandular cells, to judge recovery (HPA tissue IHC: High in gallbladder glandular cells). Check tissue preservation and the no-primary control before attributing weak signal to retrieval (standard IHC practice).
Could fixation explain uneven STK26 staining across my paraffin sections?
The selected tissue-IHC caption describes a paraffin section but does not state its fixative, so target-specific fixation sensitivity is unknown (datasheet A09552-2). Record the fixative and processing history for each specimen before comparing STK26 intensity across cases (standard IHC practice). Compare similarly processed sections using the same EDTA pH 8.0 retrieval and 2 μg/ml primary antibody conditions (datasheet A09552-2; standard IHC practice). Inspect morphology and include a staining control from the same run when uneven signal follows tissue boundaries or damaged areas (standard IHC practice). Do not infer a preferred fixative from tissue expression patterns or protein topology (HPA tissue IHC; UniProt Q9P289).
Is nuclear staining compatible with the expected STK26 pattern in tissue?
Evaluate cytoplasmic and Golgi-region staining first: UniProt places STK26 in the cytoplasm and Golgi, while tissue IHC reports cytoplasmic expression in a few tissues (UniProt Q9P289; HPA tissue IHC). HPA subcellular imaging also reports a mainly nucleoplasmic location, but labels that assignment uncertain; its Golgi and cytosol assignments are supported (HPA subcellular). Nuclear chromogen alone therefore needs stronger validation than a plausible cytoplasmic pattern, particularly when adjacent cells or section edges stain similarly (HPA subcellular; standard IHC practice). Compare the suspected compartment with a nuclear counterstain and a no-primary control, and assess preserved cell morphology before scoring (standard IHC practice).
How should isoforms and epitope uncertainty affect STK26 interpretation?
STK26 has 3 annotated isoforms and a protein kinase domain spanning residues 24–274 (UniProt Q9P289). The supplied caption gives no antibody epitope, so staining cannot be assigned to one isoform from these data (datasheet A09552-2; UniProt Q9P289). STK26 has annotated phosphorylation sites, including Thr-178 and Ser-300/304, but their effect on this antibody's tissue staining is unreported (UniProt Q9P289; datasheet A09552-2). If staining differs across specimens, check the antibody's documented immunogen or epitope information before proposing isoform-specific recognition, and use an independent specificity control where available (standard IHC practice). Report the result as STK26 immunoreactivity unless isoform selectivity has been demonstrated (standard IHC practice).
How can IF help check the cell type and compartment seen by IHC?
For the separate IF/ICC assay, pair STK26 with a marker of the expected cell type, such as an epithelial marker when checking glandular cells (HPA tissue IHC: High in gallbladder and small-intestine glandular cells; standard IF practice). Choose spectrally separated fluorophores and inspect unstained tissue in each channel before interpreting puncta against autofluorescence (standard IF practice). STK26 has no transmembrane segment and is reported in cytosol and Golgi, so permeabilisation should allow antibody access to intracellular epitopes (UniProt Q9P289; HPA subcellular; standard IF practice). Include single-label and no-primary controls when assessing overlap; IF localisation does not establish that the IHC antibody recognizes a particular isoform (standard IF practice; UniProt Q9P289).
What should I check when DAB staining appears diffuse or widespread?
Compare the stained section with a no-primary control to identify signal from the detection system or tissue rather than primary-antibody binding (standard IHC practice). The selected image used 10% goat serum block, 2 μg/ml primary antibody overnight at 4°C, and DAB detection (datasheet A09552-2). A peroxidase block before HRP detection, adequate washing, and inspection for precipitated chromogen are general ways to reduce misleading DAB signal (standard IHC practice). Reassess diffuse staining against intact cytoplasmic morphology and a known positive cell population; HPA describes STK26 tissue staining as cytoplasmic in a few tissues (HPA tissue IHC; standard IHC practice).
How should I score STK26 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because HPA reports cell-type differences and a mainly cytoplasmic tissue pattern (HPA tissue IHC). For chromogenic IHC, record the percentage of positive target cells and intensity, or calculate an H-score from 0–300 using intensity-weighted percentages (standard IHC practice). Normalise counts or stained area to the number of evaluable target cells or their measured tissue area, excluding folds, necrosis and damaged edges (standard IHC practice). Keep retrieval, 2 μg/ml primary concentration and imaging settings consistent when comparing slides, and report cytoplasmic and nuclear scores separately if both appear (datasheet A09552-2; standard IHC practice).
What would make an apparent STK26-positive cell convincing?
A convincing result places signal in intact cells with a plausible cytoplasmic or Golgi-region pattern and distinguishes stained cells from their neighbors (UniProt Q9P289; HPA tissue IHC; standard IHC practice). High staining in gallbladder glandular cells or skeletal-muscle myocytes can provide context, whereas HPA lists adipocytes and heart-muscle cardiomyocytes as not detected (HPA tissue IHC). Treat staining confined to section edges, necrotic areas, implausible cell populations or the no-primary control as possible artefact, and check endogenous peroxidase when DAB is used (standard IHC practice). HPA calls its tissue staining approved but reports low consistency with RNA expression and pending external verification, so confirm consequential findings independently (HPA tissue IHC).
Boster reagents
Best STK26 / Serine/threonine-protein kinase 26 IHC Antibodies
Two anti-STK26 antibodies have IHC images from human paraffin sections (A09552-2 and M09552 image captions). Catalog reactivity covers human and rat for A09552-2, and human, mouse, and rat for M09552 (catalog reactivity).
Real IHC data
Anti-MST4/STK26 Antibody ®
Cat # A09552-2
Real IHC data
Anti-MST4 Rabbit Monoclonal Antibody
Cat # M09552
A09552-2 has IHC images from human paraffin-embedded ovarian and colon cancer tissue (A09552-2 image captions). M09552 has an IHC image from human paraffin-embedded colon cancer tissue (M09552 image caption).
Which to pick: For tissue IHC, choose A09552-2 for the ovarian or colon examples, or monoclonal M09552 for the colon example (catalog clone; each SKU’s image captions). Neither SKU lists IF/ICC validation or an IF image, so there is no evidence-based IF/ICC pick (catalog applications and image lists). For mouse tissue, M09552 is the listed option; both list human and rat reactivity, but their IHC captions show human paraffin sections only, and neither caption reports the fixative (catalog reactivity; each SKU’s image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9P289 (STK26_HUMAN, Serine/threonine-protein kinase 26).
- Human Protein Atlas. STK26 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. STK26 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the Golgi apparatus, cytosol and centrosome..
- Human Protein Atlas. STK26 antibody validation summary (1 antibodies).
- MST4 Regulates Epithelial-Mesenchymal Transition of Choriocarcinoma by Mediating TGF-β1 Expression. OncoTargets and therapy 2020 — PMC7683511.
- PubMed PMID:11641781 — UniProt-cited evidence.
- PubMed PMID:11306563 — UniProt-cited evidence.
- PubMed PMID:11741893 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for STK26 (Serine/threonine-protein kinase 26). Expected localisation Cytoplasmic tissue staining (HPA tissue IHC); Golgi location (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A09552-2). Validated IHC antibody: A09552-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Gallbladder (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human ovarican cancer tissue; fixative not specified (datasheet A09552-2); 2. Fixation: Image fixative and duration unreported (datasheet A09552-2); 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 A09552-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A09552-2); 8. Primary antibody: Rabbit anti-STK26, 2-5 μg/ml (datasheet A09552-2); 9. Primary incubation: Overnight at 4 °C (datasheet A09552-2). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining has low consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 3 isoforms; epitope coverage needs checking (UniProt); Regulation: Serum stimulation shifts Golgi signal to puncta (UniProt). Evidence: UniProt Q9P289, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A09552-2, PMC7683511. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/STK26/immunohistochemistry-ihc-guide.