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SCG3 / Secretogranin-3 · IHC design guide
Design Immunohistochemistry for SCG3
Plan chromogenic SCG3 IHC-P using the catalog antibody at 0.5–1 μg/ml (datasheet). Use pancreatic endocrine cells as a positive control and adipocytes in adipose tissue as a negative control, then assess cytoplasmic staining in tissue context (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SCG3 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 | Cytoplasm/membrane in Bergmann glia (HPA tissue IHC) | |
| Staining pattern | Selective cytoplasmic staining in CNS, islets, adrenal medulla and GI cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Cerebellum+3 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 | Secreted SCG3 may make tissue protein and RNA patterns differ (HPA tissue IHC) | |
| Regulation | Brain, pituitary, retina: enhanced RNA (HPA RNA) | |
| Isoform / epitope | 2 isoforms; no transmembrane segment; signal peptide 1–19 cleaved (UniProt) |
Section 1
Recommended SCG3 IHC & IF Protocols
The catalog antibody protocol (datasheet) is accompanied by published IHC examples of Scg3-Phage binding, mouse retina staining, and glioma tissue microarray staining (PMC9232851; PMC11394726; PMC8262226).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet PA1071); 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 citrate buffer, pH 6.0, 20 min at 95–98 °C (standard rule: cytoplasmic / membrane 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-SCG3, 0.5-1μg/ml (datasheet PA1071) |
| 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 | SCG3-positive staining in bergmann glia - cytoplasm/membrane of cerebellum (HPA tissue IHC: High). HPA tissue profile: Selective cytoplasmic expression in CNS, islets of Langerhans, adrenal medulla and a subset of cells in the gastrointestinal tract. No signal in the no-primary control. |
💡Decision noteStart with citrate HIER at pH 6.0, 95–98 °C for 20 min (page antigen-retrieval rule); the glioma study reports heat retrieval without conditions (PMC8262226).
Section 2
What Is the Expected SCG3 Staining Pattern?
SCG3 is associated with secretory vesicles and their membranes and can also be secreted; it has no transmembrane segment (UniProt Q8WXD2 topology and subcellular location). In paraffin section IHC, expect selective cytoplasmic staining in CNS cells and pancreatic endocrine cells, with staining also reported in adrenal medulla and subsets of gastrointestinal cells (HPA: tissue IHC). HPA rates the tissue pattern Enhanced, while noting medium consistency with RNA data (HPA: reliability).
| Selective cytoplasmic staining in cerebral cortical or hippocampal neurons, or pancreatic endocrine cells (HPA: High). | This fits the reported tissue pattern (HPA: tissue IHC). A granular or vesicle-associated appearance is consistent with SCG3's secretory-vesicle location, although routine chromogenic IHC may not resolve individual vesicles (UniProt Q8WXD2 subcellular location; standard IHC practice). |
| Predominantly nuclear staining in an otherwise positive cell population (HPA: selective cytoplasmic profile). | Treat the compartment mismatch as suspect: UniProt places SCG3 in secretory vesicles, vesicle membranes and secreted material, and HPA describes cytoplasmic tissue staining (UniProt Q8WXD2 subcellular location; HPA: tissue IHC). Recheck controls before scoring it as SCG3. |
| Strong staining in adipocytes or bronchial respiratory epithelium (HPA: Not detected in those cells). | The cell-type mismatch raises concern for cross-reactivity or endogenous detection activity; it does not establish either cause by itself (HPA: tissue IHC; standard IHC practice). Compare a no-primary control and a known-positive tissue processed in the same run. |
| Diffuse chromogen across many cell types, including reported negative compartments (HPA: tissue IHC). | Broad, poorly localized staining is less persuasive than the selective cytoplasmic profile (HPA: tissue IHC). Background from detection reagents or insufficient blocking is a general IHC possibility; assess it with a no-primary control (standard IHC practice). |
| No convincing staining in pancreatic endocrine cells or cortical neurons (HPA: High). | A blank known-positive compartment makes the run difficult to interpret (HPA: tissue IHC; standard IHC practice). Check that the expected cells are present, then review the antibody's IHC validation and the run's retrieval, dilution and detection conditions. |
💡Expected SCG3 appearanceCall a positive result when staining is selective and mainly cytoplasmic in reported high-expression cells, such as cortical neurons or pancreatic endocrine cells (HPA: High; HPA: tissue IHC); dominant nuclear staining or similarly strong staining across reported negative cell types is suspect (UniProt Q8WXD2 subcellular location; HPA: Not detected).
| Cell population used for scoring (HPA: tissue IHC). | HPA reports High staining in cerebral cortical and hippocampal neurons, pancreatic endocrine cells, and cerebellar Bergmann glia, with the latter described as cytoplasm/membrane (HPA: High). Score the specified cells rather than assuming every cell in a positive organ should stain. |
| Negative comparator choice (HPA: tissue IHC). | Adipocytes in adipose tissue and respiratory epithelial cells in bronchus are reported Not detected (HPA: tissue IHC). A negative comparator is useful only when the same cell population can be identified and assessed; an entire tissue's appearance can obscure that distinction (standard IHC practice). |
| Secretory location and release (UniProt Q8WXD2 subcellular location; HPA: reliability description). | SCG3 associates with cholesterol-enriched secretory-granule membrane regions and is also annotated as secreted (UniProt Q8WXD2). HPA cautions that at least one variant is secreted, so RNA location and protein staining need not align closely (HPA: reliability description). |
| Antibody evidence (HPA: antibodies and tissue IHC). | HPA lists Enhanced IHC status for HPA006880, HPA053715 and CAB033274; its tissue summary also cites similar profiles from paired antibodies (HPA: antibodies; HPA: reliability description). Enhanced supports the reported pattern, while HPA still notes medium RNA–staining consistency and pending external verification (HPA: reliability description). |
| IF/ICC: What pattern is expected (HPA: subcellular ICC-IF)? | HPA supports a vesicular location in ICC-IF and lists images from HEK293, SH-SY5Y and U2OS (HPA: subcellular ICC-IF). That is a compartment cross-check for this IHC interpretation, not evidence that fluorescence intensity or cell-line behavior predicts paraffin-section staining (HPA: subcellular ICC-IF; standard IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive tissue is blank (HPA: High in pancreatic endocrine cells and cortical neurons). | The expected cells may be absent from the section, or the IHC run may have insufficient signal (HPA: tissue IHC; standard IHC practice). | Confirm the cells on the counterstained section; then check the IHC-validated antibody's instructions and the run's retrieval, dilution and detection steps (standard IHC practice). No SCG3-specific fixation sensitivity is reported in the supplied sources. |
| Signal is mainly nuclear (HPA: selective cytoplasmic tissue profile). | The compartment conflicts with the reported tissue pattern and vesicular annotation, suggesting nonspecific staining or an interpretation error (HPA: tissue IHC; UniProt Q8WXD2 subcellular location). | Inspect cytoplasmic staining in a reported high-expression cell population and compare the no-primary control before scoring the nuclear signal (HPA: High; standard IHC practice). |
| Reported negative cells stain strongly (HPA: Not detected in adipocytes and bronchial respiratory epithelium). | Cross-reactivity or endogenous detection activity is possible; the slide alone cannot distinguish them (HPA: tissue IHC; standard IHC practice). | Run a no-primary control and review detection blocking; compare with a known-positive cell population in the same run (standard IHC practice; HPA: High). |
| Chromogen is diffuse over the section (HPA: selective cytoplasmic tissue profile). | General IHC background may arise from detection reagents, blocking or antibody concentration (standard IHC practice). | Check the no-primary control and background outside expected cells, then optimize blocking, antibody dilution and washes using the IHC-validated antibody's instructions (standard IHC practice). |
| Only scattered cells stain in a gastrointestinal section (HPA: subset of gastrointestinal cells). | A restricted pattern can fit HPA's profile; its low-staining entries include glandular cells in stomach, duodenum and small intestine (HPA: tissue IHC). | Identify the stained cell type and score its compartment and intensity separately. Do not label the entire gastrointestinal section negative merely because most cells are unstained (HPA: tissue IHC). |
| Protein staining appears broader or narrower than local RNA expression (HPA: medium RNA–staining consistency). | At least one SCG3 protein variant is secreted, which can separate protein and RNA locations (HPA: reliability description; UniProt Q8WXD2 subcellular location). | Record the stained cells and compartment directly, and interpret RNA disagreement with HPA's stated secretion caveat and pending external verification (HPA: reliability description). |
Experiment evidence
IHC & IF images showing SCG3 staining
PA1071 · IHCAnti-Secretogranin 3 antibody, PA1071, IHC(P) IHC(P): Rat Brain Tissue
PA1071 · IHCAnti-Secretogranin 3 antibody, PA1071, IHC(P) IHC(P): Rat Brain Tissue
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000104112-SCG3/tissue/cerebral+cortex#imid_19239525
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000104112-SCG3/tissue/colon#imid_19239435
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000104112-SCG3/tissue/liver#imid_19239452
HPA · PancreasHuman Protein Atlas IHC, Pancreas. Source: https://www.proteinatlas.org/ENSG00000104112-SCG3/tissue/pancreas#imid_19239394
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA053715; green = SCG3, blue = nucleus, red = microtubules.
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA053715; green = SCG3, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SCG3 IHC & IF
🧪Run pancreas first: pancreatic endocrine cells should stain strongly (HPA: High in pancreatic endocrine cells). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); neighboring nonendocrine cells on the pancreas slide should provide a low-background reference, but confirm their staining rather than assuming they are SCG3-negative (HPA: High in pancreatic endocrine cells).
Positive control tissue: Cerebellum (Bergmann glia - cytoplasm/membrane, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SCG3 in HEK293, SH-SY5Y, U2OS, with annotated localisation: Vesicles (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; an isotype control matched to the primary antibody’s host species, immunoglobulin class and clonality where applicable; and SCG3 knockout material or a validated immunizing-peptide block as a biological specificity control (standard IHC practice). Block endogenous peroxidase in pancreatic sections for chromogenic detection, and assess tissue autofluorescence if using IF (standard IHC/IF practice).
⚠️Feasibility: A target-specific fixation window and fixation effect are unreported, and the selected PA1071 rat-brain IHC(P) caption does not state a fixative (selected-SKU tissue-IHC caption). Retrieval dependence is unreported, so optimize heat-induced retrieval on paraffin sections empirically (standard IHC practice); the supplied evidence does not establish whether frozen sections or IF would be easier. Vesicular IF staining is supported in the listed cell lines (HPA: Vesicles, supported), while pancreatic endogenous peroxidase and autofluorescence warrant background controls (standard IHC/IF practice).
HPA tissue IHC evidence for SCG3
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex. External characterization data supports antibody staining. Pending external verification. Paired antibodies with high similarity supports the protein profile.). 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 |
|---|---|---|---|---|
| Cerebellum | Bergmann glia - cytoplasm/membrane | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Hippocampus | Neuronal cells | High | Protein (IHC) | HPA → |
| Pancreas | Pancreatic endocrine cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | 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 → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SCG3 IHC Tips
Troubleshoot SCG3 staining in paraffin sections by checking retrieval, cellular pattern, controls, and scoring before interpreting signal.
How should I retrieve SCG3 antigen in paraffin sections with weak staining?
Start with citrate pH 6.0 heat-induced retrieval at 95–98 °C for 20 min (page retrieval setting). Compare a weak section with a concurrently processed positive control, such as cerebral cortex neuronal cells or pancreatic endocrine cells, where high staining is reported (HPA tissue IHC). Keep section thickness, cooling, antibody incubation, and chromogen development consistent across the comparison (standard IHC practice). If staining remains weak, test an alkaline retrieval buffer around pH 9 as a fallback on adjacent sections, checking whether signal improves without increasing background (standard IHC practice).
Could fixation explain weak or uneven SCG3 staining?
Target-specific sensitivity of SCG3 to fixative type or fixation duration is unknown from the supplied evidence (evidence payload). The catalog image documents SCG3 staining in rat brain paraffin tissue but does not state its fixative, so it cannot establish a fixation condition (PA1071 tissue-IHC caption). For troubleshooting, compare sections prepared with documented fixation and processing conditions, using a cerebral cortex neuronal-cell control when available (standard IHC practice; HPA tissue IHC). Record fixative, time before fixation, fixation duration, and section age; assess staining with matched retrieval and detection conditions before attributing a difference to fixation (standard IHC practice).
What SCG3 staining pattern should I expect within positive cells?
Look for cytoplasmic, potentially punctate staining consistent with secretory vesicles, while assessing cell identity and morphology in the counterstained section (UniProt Q8WXD2 localisation; HPA subcellular: vesicles supported; standard IHC practice). SCG3 associates with secretory granule membranes through cholesterol-enriched lipid rafts, yet has no transmembrane segment (UniProt Q8WXD2 localisation and topology). High tissue staining is reported in cerebral cortex and hippocampal neuronal cells, pancreatic endocrine cells, and cerebellar Bergmann glia with cytoplasmic or membrane staining (HPA tissue IHC). Treat isolated nuclear staining or a uniform cell-surface rim without a plausible cytoplasmic component as a reason to recheck specificity and detection controls (standard IHC practice; UniProt Q8WXD2 localisation).
How do SCG3 processing and isoforms affect antibody interpretation?
SCG3 has 2 annotated isoforms, and its precursor contains a signal peptide at residues 1–19 followed by a chain spanning 20–468 (UniProt Q8WXD2 processing and isoforms). Without a supplied antibody epitope, staining cannot be assigned to either isoform or to a particular region of the processed chain (evidence payload; standard IHC interpretation). The record lists glycosylation sites at residues 37, 216, 231, and 359, but supplies no evidence that these modifications alter this antibody’s IHC signal (UniProt Q8WXD2 modifications; evidence payload). Consult the antibody’s documented epitope before using staining differences to infer isoform abundance or processing (standard IHC practice).
How can I assess SCG3 in a multiplex immunofluorescence experiment?
Pair SCG3 with a validated marker identifying the expected cell population, then inspect whether its signal lies within those cells and has a vesicular pattern (HPA tissue IHC; HPA subcellular: vesicles supported; standard IF practice). Choose fluorophores after checking tissue autofluorescence in an unstained section, and place the weaker signal in a cleaner spectral channel (standard IF practice). For intracellular epitopes, use controlled permeabilisation; because this antibody’s epitope and its side of the granule membrane are unspecified, optimise permeabilisation against signal and morphology rather than assuming epitope accessibility (evidence payload; UniProt Q8WXD2 topology; standard IF practice). Include single-label and secondary-only controls to evaluate bleed-through and nonspecific fluorescence (standard IF practice).
How do I reduce diffuse brown staining without losing SCG3 signal?
First inspect a no-primary control for staining from the detection system, then compare it with the SCG3 section at the same development time (standard IHC practice). Apply a peroxidase block before chromogenic detection and check whether residual enzyme activity or excessive DAB development explains the background (standard IHC practice). Optimise antibody concentration and incubation using matched positive and lower-expression sections, while keeping retrieval at citrate pH 6.0, 95–98 °C for 20 min initially (standard IHC practice; page retrieval setting). Preserve cytoplasmic detail and counterstain visibility when adjusting washes or chromogen time; a darker whole section alone does not establish stronger SCG3 expression (standard IHC practice).
What is a defensible way to score SCG3 IHC across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because reported SCG3 staining is selective across tissues and is associated with vesicles (HPA tissue IHC; HPA subcellular: vesicles supported). Within matched regions, report the percentage of positive target cells and an intensity-based H-score, recording the positivity threshold before comparing samples (standard IHC practice). If counting stained cells per mm², also report total eligible cells per mm² so changes in cell density do not masquerade as changes in SCG3 positivity (standard IHC practice). Normalise comparisons to eligible cells or matched tissue area, and keep retrieval, imaging, and chromogen development consistent (standard IHC practice).
When is an apparent SCG3-positive IHC result likely to be artefactual?
A convincing result places signal in plausible cells with cytoplasmic or vesicular distribution; neuronal cells and pancreatic endocrine cells have reported high staining (HPA tissue IHC; HPA subcellular: vesicles supported). Recheck isolated nuclear signal or staining confined to an unexpected compartment against morphology and a no-primary control (UniProt Q8WXD2 localisation; standard IHC practice). Be cautious with signal restricted to section edges or necrotic regions, and with staining also present in a no-primary control after peroxidase detection (standard IHC practice). Interpret tissue-level disagreement carefully because SCG3 has a secreted variant and tissue RNA and protein locations may differ (HPA tissue IHC reliability description).
Boster reagents
Best SCG3 / Secretogranin-3 IHC Antibodies
PA1071 has IHC(P) images from rat brain and human rectal cancer tissue (PA1071 image alts). ICC is listed for human samples; IHC reactivity covers human, mouse, and rat (catalog: dilution_raw).
Real IHC data
Anti-Secretogranin 3/SCG3 Antibody ®
Cat # PA1071
PA1071 is listed for IHC in human, mouse, and rat, and ICC in human (catalog: dilution_raw). Its IHC(P) captions show rat brain and human rectal cancer tissue (PA1071 image alts); no IF image is supplied (catalog: IF image alts).
Which to pick: For tissue IHC, choose PA1071 for paraffin sections: its IHC(P) captions show rat brain and human rectal cancer tissue, with the fixative unreported (PA1071 image alts). For IF/ICC, PA1071 is listed for ICC at 0.5–1 μg/ml in human samples, but has no IF image (catalog: dilution_raw; IF image alts). For cross-species IHC, PA1071 lists human, mouse, and rat reactivity; its host is rabbit and clonality is unreported (catalog: dilution_raw, host, clone).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q8WXD2 (SCG3_HUMAN, Secretogranin-3).
- Human Protein Atlas. SCG3 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SCG3 subcellular location (ICC-IF): Localized to vesicles..
- Human Protein Atlas. SCG3 antibody validation summary (3 antibodies).
- Comparative ligandomics implicates secretogranin III as a disease-restricted angiogenic factor in laser-induced choroidal neovascularization. The FEBS journal 2022 — PMC9232851.
- Optimal Humanized Scg3-Neutralizing Antibodies for Anti-Angiogenic Therapy of Diabetic Retinopathy. International journal of molecular sciences 2024 — PMC11394726.
- SCG3 Protein Expression in Glioma Associates With less Malignancy and Favorable Clinical Outcomes. Pathology oncology research : POR 2021 — PMC8262226.
- Selectively targeting disease-restricted secretogranin III to alleviate choroidal neovascularization. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2022 — PMC8694659.
- PubMed PMID:12098761 — UniProt-cited evidence.
- PubMed PMID:12975309 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SCG3 (Secretogranin-3). Expected localisation Cytoplasm/membrane in Bergmann glia (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: PA1071 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Cerebellum (Bergmann glia - cytoplasm/membrane); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet PA1071); 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 citrate buffer, pH 6.0 , 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-SCG3, 0.5-1μg/ml (datasheet PA1071); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Secreted SCG3 may make tissue protein and RNA patterns differ (HPA tissue IHC); Isoform / epitope: 2 isoforms; no transmembrane segment; signal peptide 1–19 cleaved (UniProt); Regulation: Brain, pituitary, retina: enhanced RNA (HPA RNA). Evidence: UniProt Q8WXD2, HPA tissue IHC · Enhanced, HPA ICC-IF · vesicles., Datasheet PA1071, PMC9232851, PMC11394726. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SCG3/immunohistochemistry-ihc-guide.