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SIN3A / Paired amphipathic helix protein Sin3a · IHC design guide
Design Immunohistochemistry for SIN3A
Plan chromogenic SIN3A IHC around its widespread nuclear staining, strongest in testis (HPA tissue IHC). The catalog antibody was used at 2 μg/ml overnight at 4°C on paraffin sections, with DAB detection (datasheet A01203-2).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SIN3A 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 tissue (HPA tissue IHC) | |
| Staining pattern | Widespread nuclear staining, strongest in testis (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A01203-2) | |
| Positive control | Nasopharynx+4 more · see all | |
| Negative control | Adipose tissue+2 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 varies by cell type; some cells are undetected (HPA tissue IHC) | |
| Regulation | Developing brain: highest in ventricular zone (UniProt) | |
| Isoform / epitope | No annotated isoforms; one 1–1273 chain (UniProt) |
Section 1
Recommended SIN3A IHC & IF Protocols
The catalog antibody’s IHC protocol is paired with four published SIN3A staining protocols for liver, breast and testis sections (PMC11077365; PMC9177717; PMC6207735; PMC3423586).
| Sample | Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A01203-2) |
| Fixation | Image fixative and duration unreported (datasheet A01203-2); 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 A01203-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01203-2) |
| Primary antibody | Rabbit anti-SIN3A, 2-5 μg/ml (datasheet A01203-2) |
| Primary incubation | Overnight at 4 °C (datasheet A01203-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A01203-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SIN3A-positive staining in respiratory epithelial cells of nasopharynx (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression with highest expression in testis. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A01203-2); the published protocols used their own retrieval conditions (PMC11077365; PMC9177717; PMC6207735; PMC3423586).
Section 2
What Is the Expected SIN3A Staining Pattern?
SIN3A should appear predominantly in nuclei across many cell types (HPA: ubiquitous nuclear tissue expression; UniProt Q96ST3: nucleus). Strong examples are testis preleptotene spermatocytes, placental cytotrophoblasts and nasopharyngeal respiratory epithelial cells (HPA: High in each). The HPA tissue pattern has Enhanced reliability, meaning high consistency between antibody staining and RNA expression (HPA: tissue reliability). SIN3A has no transmembrane segment (UniProt Q96ST3 topology).
| Distinct nuclear staining in preleptotene spermatocytes, cytotrophoblasts or nasopharyngeal respiratory epithelium. | This matches three reported High cell populations (HPA: testis, placenta and nasopharynx). Judge intensity within the named cells, alongside slide controls; a positive field need not have identical staining in every cell (general IHC practice). |
| Strong staining sits chiefly in cytoplasm or along cell membranes, while nuclei remain faint. | That compartment conflicts with the reported nuclear tissue pattern (HPA: ubiquitous nuclear expression) and nuclear localisation (UniProt Q96ST3). Review staining specificity and tissue morphology before calling it SIN3A; a membrane pattern has no support from its topology (UniProt Q96ST3: no transmembrane segment). |
| The dominant signal is in adipocytes, cholangiocytes or parathyroid glandular cells. | Those named populations are reported Not detected (HPA: adipose tissue, liver and parathyroid gland). Consider cross-reactivity or endogenous detection activity, particularly when the signal lacks nuclear definition (general IHC practice). These are cell-level comparisons, not claims that the entire organs lack SIN3A. |
| A broad, hazy deposit covers nuclei and surrounding tissue without clear cell boundaries. | Diffuse background cannot establish the expected nuclear pattern (HPA: ubiquitous nuclear expression). Compare a no-primary control, examine blocking and washing, and assess whether detection reagent or chromogen contributes background (general IHC practice). |
| No nuclear signal appears in a testis section containing identifiable preleptotene spermatocytes. | Those cells are a reported High population (HPA: testis). First confirm their presence and section quality; then check the IHC-validated antibody, retrieval and detection workflow against its documented IHC-P procedure (general IHC practice). A blank slide alone does not show biological absence. |
💡Expected SIN3A appearanceCall a result positive when nuclei are clearly stained in the relevant cells, with strong staining possible in preleptotene spermatocytes, cytotrophoblasts or nasopharyngeal respiratory epithelial cells (HPA: High); dominant cytoplasmic, membranous or diffuse staining is suspect (HPA: nuclear tissue pattern; UniProt Q96ST3: nucleus).
| Cell-specific reference populations (HPA: tissue IHC). | High staining is reported in three named populations, while bronchial respiratory epithelium and several glandular populations are Medium (HPA: tissue IHC). Choose comparisons by cell type; Low or Not detected observations should not be promoted to whole-tissue negative controls. |
| Subcellular assignment (UniProt Q96ST3; HPA: tissue IHC). | Both sources support a nuclear result. UniProt also lists the nucleolus, with recruitment by SAP30L (UniProt Q96ST3: subcellular location). The HPA tissue profile establishes ubiquitous nuclear staining, so a distinct nucleolar IHC signal is not required for a positive call. |
| Antibody-level support (HPA: antibody validation). | HPA047213 and HPA062123 have Enhanced IHC validation; CAB004506 has Supported IHC validation (HPA: antibody validation). These statuses support their reported applications but do not establish that an unrelated catalog antibody gives the same intensity in every tissue. |
| Target structure and modifications (UniProt Q96ST3). | SIN3A has no signal peptide, propeptide or transmembrane segment; its listed chain spans residues 1–1273 (UniProt Q96ST3). Reported phosphorylation and acetylation sites do not, by themselves, establish an IHC epitope effect or a different expected compartment. |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive testis cells show no nuclear staining (HPA: High in preleptotene spermatocytes). | The relevant cells may be absent from the examined field, or an IHC workflow step may have failed (general IHC practice). | Confirm cell identity and section quality, then check the catalog antibody's IHC-P instructions for retrieval, dilution, incubation and detection; compare a same-run positive control (general IHC practice). |
| Signal is widespread and hazy rather than nuclear (HPA: expected nuclear pattern). | Background from blocking, washing, detection reagents or chromogen can obscure localisation (general IHC practice). | Inspect a no-primary control and adjust the documented blocking, washing or detection workflow as indicated by that control (general IHC practice). |
| Cytoplasmic or membranous staining dominates (HPA: nuclear tissue pattern). | Nonspecific binding or background is possible; SIN3A is nuclear and lacks a transmembrane segment (UniProt Q96ST3). | Compare nuclear detail with a known-positive cell population and check a no-primary control before scoring the extranuclear signal (general IHC practice; HPA: High reference populations). |
| Adipocytes or cholangiocytes stain strongly (HPA: Not detected in those cells). | Cell-level discordance can indicate cross-reactivity or endogenous detection activity (general IHC practice). | Check whether staining is nuclear, compare the no-primary control and confirm the same-run positive population before assigning specificity (general IHC practice; HPA: nuclear tissue pattern). |
| A Low reference population appears faint or negative, such as cortical neurons (HPA: Low). | Weak staining is consistent with that reported level; it cannot by itself distinguish low expression from a weak run (HPA: cerebral cortex; general IHC practice). | Interpret it beside a High reference population processed in the same run, such as preleptotene spermatocytes (HPA: testis; general IHC practice). |
| IF/ICC question: where should the signal appear in imaged cells? | HPA reports enhanced nucleoplasmic localisation in ICC-IF (HPA: subcellular localisation). | Expect nucleoplasmic signal when interpreting IF/ICC images (HPA: subcellular localisation). Use the separate IF/ICC guide for its workflow; the tissue IHC pattern does not specify an IF/ICC protocol. |
Experiment evidence
IHC & IF images showing SIN3A staining
A01203-2 · IHCIHC analysis of mSin3A/SIN3A using anti-mSin3A/SIN3A antibody (A01203-2). mSin3A/SIN3A was detected in a paraffin-embedded section of human
A01203-2 · IHCIHC analysis of mSin3A/SIN3A using anti-mSin3A/SIN3A antibody (A01203-2). mSin3A/SIN3A was detected in a paraffin-embedded section of human
A01203-2 · IFIF analysis of mSin3A/SIN3A and Tubulin alpha using anti-mSin3A/SIN3A antibody (A01203-2) and anti-Tubulin alpha antibody (M03989-3). mSin3A
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000169375-SIN3A/tissue/cerebral+cortex#imid_17245139
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000169375-SIN3A/tissue/colon#imid_17245065
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000169375-SIN3A/tissue/liver#imid_17245058
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000169375-SIN3A/tissue/kidney#imid_17245075
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB004506; green = SIN3A, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB004506; green = SIN3A, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SIN3A IHC & IF
🧪Run nasopharynx first: respiratory epithelial cells should show nuclear staining (HPA: High in respiratory epithelial cells; UniProt Q96ST3: nuclear localization). Use adipose tissue as the negative tissue, assessing adipocytes (HPA: Not detected in adipocytes); on the nasopharynx slide, cells without nuclear signal can show background staining, but their SIN3A status is unverified (HPA: only respiratory epithelial cells are listed for nasopharynx).
Positive control tissue: Nasopharynx (Respiratory epithelial cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SIN3A in A-431, U-251MG, Rh30, SiHa, U2OS, RPTEC/TERT1, hTERT-RPE1 (serum starved), U2OS, siRNA 2 (10x), U2OS, siRNA 2 (40x), U2OS, scrambled (10x), U2OS, scrambled (40x), with annotated localisation: Nucleoplasm (enhanced) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) section, a concentration-matched rabbit IgG isotype control for the catalog antibody, and a SIN3A knockout biological control where available (caption: rabbit primary antibody; standard IHC control practice). Quench endogenous peroxidase and check for nonspecific chromogen deposition in the nasopharynx section (caption: peroxidase detection with DAB; standard chromogenic IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected A01203-2 tissue-IHC caption does not report a fixative (selected-SKU caption: fixative unreported). Heat-mediated retrieval in EDTA at pH 8.0 was used for the paraffin-section example; that example does not establish that retrieval is required in every specimen (selected-SKU caption: EDTA retrieval, pH 8.0). The evidence does not establish that frozen sections or IF are easier; for nasopharynx, distinguish nuclear signal from staining over respiratory epithelial mucus (HPA: High in respiratory epithelial cells; standard IHC interpretation practice).
HPA tissue IHC evidence for SIN3A
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 |
|---|---|---|---|---|
| Nasopharynx | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Placenta | Cytotrophoblasts | High | Protein (IHC) | HPA → |
| Testis | Preleptotene spermatocytes | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Medium | Protein (IHC) | HPA → |
Section 3
Advanced SIN3A IHC Tips
Troubleshoot SIN3A staining in paraffin section IHC by checking nuclear localisation, the catalog antibody’s documented retrieval conditions, and matched controls.
Which retrieval conditions should I try first for weak SIN3A nuclear staining?
Start with heat-mediated retrieval in EDTA at pH 8.0 for the catalog antibody (datasheet A01203-2). The documented paraffin-section example used that retrieval condition before overnight primary incubation at 4°C (datasheet A01203-2). If nuclear staining remains weak, adjust heating time or cooling consistently across a test series while preserving a known positive section (standard IHC practice; HPA: high SIN3A staining in testis preleptotene spermatocytes). Compare nuclear signal with tissue damage and background, since excessive retrieval can impair morphology (standard IHC practice). Record the retrieval conditions alongside antibody concentration before attributing weak staining to low SIN3A expression (standard IHC practice).
Could fixation explain variable SIN3A staining across paraffin sections?
Target-specific fixation sensitivity is unknown: the selected tissue-IHC caption describes a paraffin-embedded section but does not state its fixative (datasheet A01203-2). Record each specimen’s fixative, fixation duration, processing history, and section age before comparing nuclear staining (standard IHC practice). Keep retrieval at EDTA pH 8.0 and primary concentration at 2 μg/ml during the initial comparison, matching the documented conditions (datasheet A01203-2). Include sections processed together and a positive reference section to distinguish a batch problem from specimen variation (standard IHC practice). Do not assign a SIN3A-specific fixation effect without a controlled comparison using the same antibody (standard IHC practice).
Where should credible SIN3A chromogenic signal appear?
Score staining primarily in nuclei, consistent with SIN3A’s nuclear localisation and the nucleoplasmic signal reported by HPA (UniProt Q96ST3 localisation; HPA: nucleoplasm, enhanced). Nucleolar staining can also be biologically plausible because SAP30L recruits SIN3A to the nucleolus (UniProt Q96ST3 localisation). Examine whether DAB signal occupies the nucleus within intact cells, using the counterstain to define nuclear boundaries (standard IHC practice). Widespread cytoplasmic or surface staining needs additional specificity checks because SIN3A has no transmembrane segment and is reported as nuclear (UniProt Q96ST3 topology and localisation). Compare suspect regions with a no-primary control and with a tissue region expected to stain (standard IHC practice).
How do epitope uncertainty and SIN3A modifications affect IHC interpretation?
The supplied record lists 0 isoforms and three PAH domains, but the selected caption does not identify the antibody’s epitope (UniProt Q96ST3 isoforms and domains; datasheet A01203-2). SIN3A has documented phosphorylation and acetylation sites, including phosphoserine 10 and acetyllysine 469 (UniProt Q96ST3 modified residues). Those annotations alone do not establish whether a modification affects this antibody’s tissue staining (UniProt Q96ST3 modified residues; datasheet A01203-2 epitope unreported). If staining differs between specimens, first compare processing and retrieval under matched conditions (standard IHC practice). An epitope-dependent explanation requires epitope information or a controlled comparison with an independent antibody (standard IHC practice).
How should I check a SIN3A result with multiplex immunofluorescence?
Use IF as a cross-check for nuclear localisation; this catalog antibody’s supplied tissue example documents chromogenic IHC, not an IF protocol (datasheet A01203-2). Pair SIN3A with a marker for the cell type under study and a nuclear counterstain, then inspect signal within segmented nuclei (standard IF practice; HPA: SIN3A nucleoplasmic localisation). Select fluorophores after checking tissue autofluorescence and include single-stain controls to assess spectral bleed-through (standard IF practice). SIN3A is intracellular and nuclear, with no transmembrane segment, so permeabilisation must allow antibody access to nuclear epitopes (UniProt Q96ST3 topology and localisation; standard IF practice). Optimise permeabilisation on a small test set because the antibody’s exact epitope is unreported (datasheet A01203-2; standard IF practice).
How can I reduce diffuse DAB background without losing SIN3A signal?
Begin by checking whether excess DAB lies outside nuclei, where SIN3A staining is less consistent with its reported localisation (UniProt Q96ST3 localisation; HPA: nucleoplasm). The documented section used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and a peroxidase-conjugated secondary (datasheet A01203-2). Compare no-primary and secondary-only controls, then titrate primary concentration and washing if nonspecific deposit persists (standard IHC practice). Include an endogenous peroxidase block before HRP detection and check whether pigment or necrotic material resembles DAB (standard chromogenic IHC practice). Preserve identical development times across comparison sections so background changes remain interpretable (standard IHC practice).
What is a defensible way to quantify SIN3A IHC staining? ⚠ ANSWER MARKED FOR VERIFICATION
Define the scored cell population and nuclear region before measuring SIN3A, because HPA reports nuclear expression across many tissues and cell types (HPA: ubiquitous nuclear expression). For chromogenic sections, report the percentage of positive nuclei and an H-score based on nuclear intensity categories, using the same thresholds across specimens (standard IHC quantification practice). If cell abundance varies, also report positive nuclei per mm² of viable tissue and normalise percentages to all evaluable nuclei in the selected cell population (standard IHC quantification practice). Exclude folds, necrosis, and section edges using prespecified rules (standard IHC quantification practice). Keep retrieval, staining, imaging, and threshold settings matched across the comparison set (standard IHC quantification practice).
How do I distinguish true SIN3A positivity from staining artefacts?
A credible result is predominantly nuclear within intact cells, matching the reported SIN3A localisation and HPA tissue profile (UniProt Q96ST3 localisation; HPA: ubiquitous nuclear expression). The selected caption demonstrates staining in paraffin-embedded human breast cancer tissue, but does not report the fixative or establish every stained cell as specific (datasheet A01203-2). Compare suspect staining with a positive reference such as testis preleptotene spermatocytes and a no-primary control (HPA: high in preleptotene spermatocytes; standard IHC practice). Treat isolated cytoplasmic deposits, section-edge enhancement, necrotic regions, and endogenous peroxidase signal as possible artefacts requiring control review (UniProt Q96ST3 localisation; standard IHC practice). Interpret low or absent staining within the scored cell population and processing context (standard IHC practice).
Boster reagents
Best SIN3A / Paired amphipathic helix protein Sin3a IHC Antibodies
A01203-2 has pictured IHC staining in human paraffin sections and IF staining in human ovarian cancer sections and U20S cells (catalog image captions); M01203 lists IHC and IF/ICC for human, mouse, and rat (catalog applications and reactivity).
Real IHC data
Anti-mSin3A/SIN3A Antibody ®
Cat # A01203-2
A01203-2 has pictured IHC results in human breast, larynx, lung, and ovarian cancer paraffin sections, plus IF results in human ovarian cancer sections and U20S cells (catalog image captions). M01203 lists IHC and IF/ICC applications and human, mouse, and rat reactivity, but has no IHC or IF image caption in the payload (catalog applications, reactivity, and image captions).
Which to pick: Choose A01203-2 for human tissue IHC: its pictured paraffin sections used EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody; the fixative is unreported (A01203-2 IHC image captions). A01203-2 also has pictured IF in an ovarian cancer paraffin section and U20S cells, with 5 μg/ml primary antibody (A01203-2 IF image captions). For mouse samples, consider rabbit monoclonal M01203, which lists mouse reactivity and IHC and IF/ICC applications, while A01203-2 lists human and rat reactivity (catalog title, applications, and reactivity).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q96ST3 (SIN3A_HUMAN, Paired amphipathic helix protein Sin3a).
- Human Protein Atlas. SIN3A tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SIN3A subcellular location (ICC-IF): Localized to the nucleoplasm..
- Human Protein Atlas. SIN3A antibody validation summary (3 antibodies).
- Oxidative stress promotes liver fibrosis by modulating the microRNA-144 and SIN3A-p38 pathways in hepatic stellate cells. International journal of biological sciences 2024 — PMC11077365.
- Suppression of SIN3A by miR-183 Promotes Breast Cancer Metastasis. Molecular cancer research : MCR 2022 — PMC9177717.
- A novel somatic mutation of SIN3A detected in breast cancer by whole-exome sequencing enhances cell proliferation through ERα expression. Scientific reports 2018 — PMC6207735.
- Chromatin associated Sin3A is essential for male germ cell lineage in the mouse. Developmental biology 2012 — PMC3423586.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:17974005 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SIN3A (Paired amphipathic helix protein Sin3a). Expected localisation Nuclear staining in tissue (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A01203-2). Validated IHC antibody: A01203-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Nasopharynx (Respiratory epithelial cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A01203-2); 2. Fixation: Image fixative and duration unreported (datasheet A01203-2); 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 A01203-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01203-2); 8. Primary antibody: Rabbit anti-SIN3A, 2-5 μg/ml (datasheet A01203-2); 9. Primary incubation: Overnight at 4 °C (datasheet A01203-2). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining varies by cell type; some cells are undetected (HPA tissue IHC); Isoform / epitope: No annotated isoforms; one 1–1273 chain (UniProt); Regulation: Developing brain: highest in ventricular zone (UniProt). Evidence: UniProt Q96ST3, HPA tissue IHC · Enhanced, HPA ICC-IF · nucleoplasm., Datasheet A01203-2, PMC11077365, PMC9177717. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SIN3A/immunohistochemistry-ihc-guide.