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SOX15 / Transcription factor SOX-15 · IHC design guide
Design Immunohistochemistry for SOX15
Use nuclear and nucleolar staining in squamous epithelia as a SOX15 tissue-IHC reference pattern (HPA tissue IHC). This guide pairs that pattern with a paraffin-section antibody workflow (datasheet A07722-1) and flags presumed off-target staining (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SOX15 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 and nucleolar tissue staining (HPA tissue IHC) | |
| Staining pattern | Most abundant in squamous epithelial nuclei and nucleoli (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A07722-1) | |
| Positive control | Cervix+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 | Presumed off-target staining may confound interpretation (HPA tissue IHC) | |
| Regulation | Tissue-enhanced RNA in esophagus and skin (HPA tissue RNA) | |
| Isoform / epitope | Two isoforms; isoform-specific epitope effects are unknown (UniProt) |
Section 1
Recommended SOX15 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A07722-1) is followed by three published SOX15 staining protocols (PMC5643738; PMC5122168; PMC2762865).
| Sample | Paraffin-embedded mouse brain tissues; fixative not specified (datasheet A07722-1) |
| Fixation | Image fixative and duration unreported (datasheet A07722-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A07722-1) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A07722-1) |
| Primary antibody | Rabbit anti-SOX15, 0.5-1μg/ml (datasheet A07722-1) |
| Primary incubation | Overnight at 4 °C (datasheet A07722-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A07722-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SOX15-positive staining in squamous epithelial cells of cervix (HPA tissue IHC: Medium). HPA tissue profile: Nuclear and nucleolar expression in a group of tissues, most abundant in squamous epithelia. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated citrate retrieval at pH 6 (datasheet A07722-1); a published SOX15 IHC protocol also uses this condition (PMC5122168).
Section 2
What Is the Expected SOX15 Staining Pattern?
SOX15 is a nuclear transcription factor with no transmembrane segment (UniProt O60248: subcellular location and topology). In paraffin sections, expect nuclear and sometimes nucleolar staining, most abundant in squamous epithelia (HPA: tissue IHC profile). HPA rates its tissue IHC evidence Enhanced but reports medium consistency with RNA data and presumed off-target binding that was disregarded (HPA: tissue IHC reliability). Interpret each cell population and compartment together.
| Nuclear staining in squamous epithelial cells, with possible nucleolar accentuation. | This fits the reported tissue pattern. HPA records medium staining in squamous cells of cervix, esophagus, oral mucosa, and vagina; its overall profile includes nuclear and nucleolar expression (HPA: tissue IHC). Judge the epithelial cells themselves, since staining elsewhere on the section does not establish the expected pattern. |
| Predominantly cytoplasmic staining, with little or no nuclear staining in expected positive cells. | Treat this as a questionable IHC result: the dominant location conflicts with SOX15's nuclear annotation and HPA's tissue IHC profile (UniProt O60248: subcellular location; HPA: tissue IHC). Review the matched negative control and detection steps before scoring it as SOX15. ICC-IF vesicle staining alone cannot validate a cytoplasmic IHC pattern. |
| Strong staining in a cell population reported as undetected, such as adipocytes or bronchial respiratory epithelium. | HPA reports SOX15 as not detected in those respective cell populations (HPA: tissue IHC). Unexpected chromogen could reflect antibody cross-reactivity or endogenous detection activity (general IHC practice). Compare the same cell type across a positive section, a negative control, and the test section; tissue-wide color alone is insufficient. |
| Diffuse color across nuclei, cytoplasm, and extracellular areas, without a clear cell pattern. | This lacks the nuclear and nucleolar distribution described for SOX15 in tissue IHC (HPA: tissue IHC profile). Consider nonspecific background or residual chromogenic detection activity (general IHC practice). Check whether the negative control shows similar color, then reassess blocking, washes, and detection conditions before assigning positive cells. |
| No nuclear signal in a well-preserved, expected positive cell population. | A blank result in squamous epithelium or skin basal cells conflicts with their reported medium staining (HPA: tissue IHC). It does not by itself prove SOX15 absence: assess the positive control, section integrity, retrieval, antibody dilution, and detection run (general IHC practice). HPA reports medium consistency with RNA and disregarded presumed off-target binding, so avoid treating one section as definitive (HPA: tissue IHC reliability). |
💡Expected SOX15 appearanceCall a convincing positive result medium nuclear staining, sometimes nucleolar, in squamous epithelial cells or skin basal cells (HPA: tissue IHC); diffuse extranuclear color or isolated staining of HPA-undetected cell types is suspect (HPA: tissue IHC; general IHC practice).
| Tissue and cell selection | HPA reports medium staining in cervix, esophagus, oral mucosa, and vaginal squamous epithelium, skin basal cells, and testis pachytene spermatocytes (HPA: tissue IHC). Choose an expected positive population that can be identified on the section; assess the named cells rather than averaging the entire tissue. |
| Antibody evidence | HPA067196 has Enhanced IHC validation, whereas no IHC status is listed for HPA074049 (HPA: antibody validation). The tissue profile still carries a medium RNA–staining consistency caveat and notes disregarded presumed off-target binding (HPA: tissue IHC reliability). Keep that distinction when comparing an IHC-validated antibody with another reagent. |
| Molecular annotation | SOX15 is a 233-amino-acid nuclear protein with two annotated isoforms, one annotated phosphoserine, and no signal peptide or propeptide (UniProt O60248). These facts support a nuclear expectation, but the supplied record gives no antibody epitope or isoform coverage; do not infer a retrieval setting or isoform-specific staining pattern from them. |
| IF/ICC Q: where is SOX15 seen? | A: HPA places it mainly in the nucleoplasm, with additional approved nucleolar and vesicle localization in ICC-IF (HPA: subcellular). This is a localization cross-check, not an IHC protocol or evidence that vesicle staining should dominate a paraffin section. The cited ICC-IF image lines are A-431, HaCaT, and U2OS (HPA: subcellular). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in squamous epithelium used as a positive reference. | The expected cells show medium staining in HPA tissue IHC; a failed run or unsuitable assay conditions remain possible (HPA: tissue IHC; general IHC practice). | Confirm the cell layer and section quality, then review the run's positive control, retrieval, antibody dilution, and detection steps (general IHC practice). Do not declare biological absence from this result alone. |
| Only cytoplasmic staining appears in an expected positive area. | A cytoplasmic-only pattern disagrees with the nuclear tissue profile (HPA: tissue IHC) and nuclear UniProt annotation (UniProt O60248). | Inspect nuclear counterstain and morphology, compare a matched negative control, and reassess nonspecific staining before scoring the cells (general IHC practice). |
| Nucleoli stain more clearly than surrounding nuclei. | Nucleolar staining can accompany nuclear staining in tissue IHC (HPA: tissue IHC profile); ICC-IF also lists nucleoli as an approved additional location (HPA: subcellular). | Score the correct cell population and document both nuclear and nucleolar appearance; compare controls if the signal is exclusively nucleolar or unexpectedly widespread (general IHC practice). |
| Adipocytes or bronchial respiratory epithelial cells stain strongly. | Those cell populations are reported as not detected (HPA: tissue IHC); cross-reactivity or endogenous chromogenic activity may explain unexpected color (general IHC practice). | Compare neighboring expected positive cells and a matched negative control; review blocking and detection conditions before interpreting the unexpected staining (general IHC practice). |
| Diffuse chromogen obscures cell boundaries and nuclei. | Nonspecific background or endogenous detection activity can obscure a compartment-specific IHC pattern (general IHC practice). | Examine the negative control, then review blocking, washes, antibody dilution, and detection conditions; rescore only when nuclei and cell types remain distinguishable (general IHC practice). |
| A test section disagrees with the selected reference tissue. | HPA reports medium consistency between antibody staining and RNA and disregarded presumed off-target binding (HPA: tissue IHC reliability); sampling and assay variation also require review (general IHC practice). | Compare the same named cell type across sections, confirm positive and negative controls, and record the discrepancy without overriding cell-level evidence (general IHC practice). |
Experiment evidence
IHC & IF images showing SOX15 staining
A07722-1 · IHCIHC analysis of SOX15 using anti-SOX15 antibody (A07722-1). SOX15 was detected in paraffin-embedded section of mouse brain tissues. Heat med
A07722-1 · IHCIHC analysis of SOX15 using anti-SOX15 antibody (A07722-1). SOX15 was detected in paraffin-embedded section of rat testis tissues. Heat medi
A07722-1 · IFIF analysis of SOX15 using anti-SOX15 antibody (A07722-1). SOX15 was detected in immunocytochemical section of A431 cell. Enzyme antigen ret
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000129194-SOX15/tissue/cerebral+cortex#imid_18760016
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000129194-SOX15/tissue/colon#imid_18759942
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000129194-SOX15/tissue/liver#imid_18759951
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000129194-SOX15/tissue/kidney#imid_18759936
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA067196; green = SOX15, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA067196; green = SOX15, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SOX15 IHC & IF
🧪Run skin first: cells in its basal layer show medium SOX15 staining (HPA: skin, cells in basal layer, Medium). Use adipose tissue as the negative tissue, where adipocytes are not detected (HPA: adipose tissue, adipocytes, Not detected); on the skin slide, score signal in other cells separately as internal background, since their SOX15 status is not specified by the supplied HPA row (HPA: skin, cells in basal layer, Medium).
Positive control tissue: Cervix (Squamous epithelial cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SOX15 in A-431, HaCaT, U2OS, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) slide, a concentration-matched rabbit IgG isotype control, and SOX15 knockout tissue if available; the caption identifies a rabbit primary antibody (selected A07722-1 tissue-IHC caption). For chromogenic detection, block endogenous peroxidase and check for endogenous biotin because the reported method uses a biotinylated secondary, streptavidin–biotin complex, and DAB (selected A07722-1 tissue-IHC caption).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A07722-1 tissue-IHC caption does not state the fixative. The reported paraffin-section method uses citrate retrieval at pH 6 for 20 minutes; whether SOX15 staining depends on that retrieval condition is unreported (selected A07722-1 tissue-IHC caption). Whether frozen-section IF is easier is unestablished by the supplied evidence; when scoring skin DAB staining, distinguish brown melanin pigment from the expected nuclear signal (UniProt O60248: nucleus; HPA: skin, cells in basal layer, Medium).
HPA tissue IHC evidence for SOX15
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Presumed off target binding observed and disregarded.). 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 |
|---|---|---|---|---|
| Cervix | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Oral mucosa | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Skin | Cells in basal layer | Medium | Protein (IHC) | HPA → |
| Testis | Pachytene spermatocytes | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SOX15 IHC Tips
Troubleshoot SOX15 staining in paraffin sections by checking retrieval, nuclear localisation, controls, and cell-specific scoring; IF considerations are covered separately.
What retrieval conditions should I try first for weak SOX15 staining?
Start with heat-mediated retrieval in citrate buffer at pH 6 for 20 minutes (datasheet A07722-1). The catalog antibody’s paraffin-section image used this treatment before an overnight incubation at 1 μg/mL and 4°C (datasheet A07722-1). If nuclear staining is weak, check that sections remained covered by retrieval solution and compare a fresh section processed with the same heating and cooling conditions (standard IHC practice). Titrate antibody concentration only after retrieval is reproducible, because changing both variables obscures the cause of a weak signal (standard IHC practice). Judge improvement by nuclear signal and background in the same tissue compartments (UniProt O60248 localisation; standard IHC practice).
Could fixation explain variable SOX15 staining between paraffin blocks?
The selected SOX15 paraffin-section caption does not report a fixative, so target-specific fixation sensitivity is unknown (datasheet A07722-1). Record each block’s fixative and processing history, then compare sections at the same thickness with the same citrate pH 6, 20-minute retrieval and staining run (datasheet A07722-1; standard IHC practice). Include a previously staining control section in each run to distinguish block variation from a change in detection performance (standard IHC practice). If a block stays negative, assess nuclear preservation and staining of an independent nuclear control before attributing the result to absent SOX15 (UniProt O60248 localisation; standard IHC practice). Do not infer fixation sensitivity from tissue-expression patterns or the protein’s sequence annotations.
Should SOX15 staining be nuclear, nucleolar, or cytoplasmic?
Prioritise nuclear staining when reading chromogenic SOX15 sections, because SOX15 is annotated as nuclear and its main approved subcellular location is the nucleoplasm (UniProt O60248 localisation; HPA subcellular). Nucleolar localisation is also reported, while vesicular localisation is an additional observation from cell imaging rather than a tissue-IHC scoring rule (HPA subcellular). Compare the DAB signal with a nuclear counterstain and inspect nuclei at high magnification before assigning a positive cell (standard IHC practice). A diffuse cytoplasmic field without convincing nuclear enrichment deserves scrutiny, especially where tissue edges stain intensely (UniProt O60248 localisation; standard IHC practice). Report nuclear and nucleolar patterns separately when they can be resolved (HPA subcellular; standard IHC practice).
Can isoforms or phosphorylation change how I interpret SOX15 IHC?
SOX15 has 2 annotated isoforms, but the supplied catalog caption does not map the antibody epitope or establish isoform coverage (UniProt O60248 isoforms; datasheet A07722-1). A phosphoserine is annotated at residue 37; the payload does not show whether that modification affects antibody binding (UniProt O60248 modified residues). Therefore, treat a negative section as a staining result under the tested conditions, not proof that every SOX15 form is absent (standard IHC practice). If isoform discrimination matters, obtain the antibody’s epitope information and compare it with both isoform sequences before interpreting cell-specific differences (UniProt O60248 isoforms; standard IHC practice). Keep retrieval and detection matched across compared sections (standard IHC practice).
How should I design an IF follow-up to the SOX15 IHC result?
Treat IF/ICC as a separate assay: the catalog caption documents paraffin-section chromogenic IHC, not an IF dilution or fixation condition (datasheet A07722-1). Multiplex SOX15 with an epithelial marker when examining squamous epithelium, where HPA reports nuclear and nucleolar SOX15 staining, and include a nuclear counterstain for cell assignment (HPA tissue IHC; standard IF practice). Because SOX15 is nuclear and has no annotated transmembrane segment, use controlled permeabilisation to give antibody access to intracellular epitopes, then optimise it for the chosen fixation method (UniProt O60248 localisation and topology; standard IF practice). Choose spectrally separated fluorophores and assess an unstained section for tissue autofluorescence before selecting a signal channel (standard IF practice).
How can I distinguish SOX15 signal from chromogenic background?
The catalog paraffin-section workflow used 10% goat serum, a biotinylated secondary, a streptavidin–biotin complex, and DAB (datasheet A07722-1). Include a section without primary antibody to expose secondary, endogenous biotin, or chromogen-associated background, and apply a peroxidase block for the DAB workflow (standard IHC practice). If widespread staining persists, check whether it follows tissue edges, damaged areas, or endogenous pigment rather than intact nuclei (standard IHC practice; UniProt O60248 localisation). Compare nuclear signal with the matched control before changing antibody concentration or block conditions (standard IHC practice). HPA reports presumed off-target staining in its tissue assessment, so an isolated brown signal needs cellular and compartmental support (HPA tissue IHC).
What is a defensible way to quantify SOX15-positive cells? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue compartment and nuclear positivity threshold before scoring, then apply the same rules to every section in the comparison (standard IHC practice; UniProt O60248 localisation). Report the percentage of positive nuclei and, if intensity matters, an H-score from 0–300 calculated as the sum of each intensity category multiplied by its percentage of cells (standard IHC practice). For spatial questions, report positive nuclei per mm² of evaluable tissue alongside the total nuclei counted (standard IHC practice). Normalise cell fractions to nuclei within the same annotated cell population, excluding folds, necrosis, and unusable edges consistently (standard IHC practice). Keep acquisition and scoring conditions fixed across groups (standard IHC practice).
When should an apparent SOX15-positive IHC result be questioned?
A convincing call should show staining in intact nuclei within an identified cell population, consistent with SOX15’s nuclear annotation and HPA’s nuclear and nucleolar tissue profile (UniProt O60248 localisation; HPA tissue IHC). Squamous epithelial cells in cervix, esophagus, oral mucosa, and vagina are reported at medium staining levels, whereas several other sampled cell populations were not detected (HPA tissue IHC). Question signal confined to cut edges, necrotic areas, or a diffuse cytoplasmic deposit, and compare it with a section lacking primary antibody to assess detection artefact (standard IHC practice). The catalog image shows mouse brain staining, while HPA’s listed caudate glial cells were not detected; keep species, region, and cell type explicit when comparing those observations (datasheet A07722-1; HPA tissue IHC).
Boster reagents
Best SOX15 / Transcription factor SOX-15 IHC Antibodies
A07722-1 has IHC images from paraffin sections of mouse brain, mouse and rat testis, and human testis cancer; its IF/ICC image shows A431 cells (catalog image captions).
Real IHC data
Anti-SOX15 Antibody ®
Cat # A07722-1
A07722-1 is listed for IHC and IF/ICC in human, mouse, and rat samples (catalog applications and reactivity). Its IHC images show mouse brain, mouse and rat testis, and human testis cancer paraffin sections; its IF/ICC image shows A431 cells (catalog image captions).
Which to pick: Choose A07722-1 for paraffin-section IHC: its own captions document citrate retrieval at pH 6 for 20 minutes and primary antibody at 1 μg/ml overnight at 4°C (A07722-1 IHC image captions). For IF/ICC, the same SKU has an A431 cell image using 2 μg/ml primary antibody (A07722-1 IF image caption). It is listed as reactive with human, mouse, and rat, with IHC images from all three species; the paraffin-section captions do not report the fixative (catalog reactivity; A07722-1 IHC image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O60248 (SOX15_HUMAN, Transcription factor SOX-15).
- Human Protein Atlas. SOX15 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SOX15 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the nucleoli and vesicles..
- Human Protein Atlas. SOX15 antibody validation summary (2 antibodies).
- SOX15 regulates proliferation and migration of endometrial cancer cells. Bioscience reports 2017 — PMC5643738.
- Enhanced expression of the stemness-related factors OCT4, SOX15 and TWIST1 in ectopic endometrium of endometriosis patients. Reproductive biology and endocrinology : RB&E 2016 — PMC5122168.
- Sox15 Methylation Inhibits Cell Proliferation Through Wnt Signaling in Hepatocellular Carcinoma. Frontiers in oncology 2022 — PMC8980349.
- Complex interplay of three transcription factors in controlling the tormogen differentiation program of Drosophila mechanoreceptors. Developmental biology 2009 — PMC2762865.
- PubMed PMID:9540826 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:16625196 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SOX15 (Transcription factor SOX-15). Expected localisation Nuclear and nucleolar tissue staining (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A07722-1). Validated IHC antibody: A07722-1 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Cervix (Squamous epithelial cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse brain tissues; fixative not specified (datasheet A07722-1); 2. Fixation: Image fixative and duration unreported (datasheet A07722-1); 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: Citrate pH 6 , 20 min (datasheet A07722-1); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A07722-1); 8. Primary antibody: Rabbit anti-SOX15, 0.5-1μg/ml (datasheet A07722-1); 9. Primary incubation: Overnight at 4 °C (datasheet A07722-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Presumed off-target staining may confound interpretation (HPA tissue IHC); Isoform / epitope: Two isoforms; isoform-specific epitope effects are unknown (UniProt); Regulation: Tissue-enhanced RNA in esophagus and skin (HPA tissue RNA). Evidence: UniProt O60248, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A07722-1, PMC5643738, PMC5122168. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SOX15/immunohistochemistry-ihc-guide.