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SCG3 / Secretogranin-3 · IHC design guide
Design Immunohistochemistry for SCG3
Plan chromogenic SCG3 IHC on paraffin sections using 0.5–1 μg/mL of the catalog antibody (datasheet: PA1071 IHC-P). Use CNS neurons or pancreatic endocrine cells as positive controls and assess selective cytoplasmic staining (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 | Cytoplasmic staining in CNS, islets and adrenal medulla (HPA tissue IHC) | |
| Staining pattern | Selective cytoplasmic staining in neurons and endocrine 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); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image PA1071) | |
| Caveat | Secreted SCG3 may complicate tissue RNA–protein concordance (HPA tissue IHC) | |
| Regulation | Stimulus-dependent regulation unreported (UniProt) | |
| Isoform / epitope | 2 isoforms; signal peptide is cleaved; epitope impact unknown (UniProt) |
Section 1
Recommended SCG3 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by a published chromogenic SCG3 IHC method for a glioma tissue microarray (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 pH 6.0 retrieval at 95–98 °C for 20 min (page antigen retrieval rule); the article does not specify retrieval conditions (PMC8262226).
Section 2
What Is the Expected SCG3 Staining Pattern?
SCG3 is vesicular, with no transmembrane segment (UniProt Q8WXD2); expect CNS and islet cytoplasm (HPA: Enhanced).
| Strong neuronal or islet cytoplasm (HPA: High). | Fits secretory vesicle localisation (UniProt Q8WXD2). |
| Nuclear-only staining. | Suspect artefact; SCG3 is vesicular (UniProt Q8WXD2). |
| Strong adipocyte staining (HPA: Not detected). | Check cross-reactivity or endogenous detection activity (general IHC practice). |
| Diffuse stain across cells and stroma. | Background may obscure selective cytoplasmic staining (HPA tissue IHC; general IHC practice). |
| No signal in cortical neurons (HPA: High). | Check assay performance before scoring SCG3 absent (general IHC practice). |
💡Expected SCG3 appearanceHigh vesicular cytoplasm in CNS or islet cells (HPA: High; UniProt Q8WXD2); nuclear-only stain is suspect.
| Secretory granule association (UniProt Q8WXD2). | Expect cytoplasmic vesicles; SCG3 can associate with granule membranes (UniProt Q8WXD2). |
| Secreted SCG3 (UniProt Q8WXD2). | Protein and RNA locations may differ (HPA reliability description). |
| 2 isoforms (UniProt Q8WXD2). | Isoform coverage depends on the antibody epitope (general IHC practice). |
| IF/ICC appearance? | Vesicular staining is supported (HPA ICC-IF); use the separate IF/ICC guide for methods. |
| Situation | Likely cause | Next action |
|---|---|---|
| No stain in pancreatic endocrine cells (HPA: High). | Possible assay failure (general IHC practice). | Check retrieval, primary dilution and detection with a positive control (general IHC practice). |
| Nuclear-only signal. | Unexpected for vesicular SCG3 (UniProt Q8WXD2). | Review controls and antibody specificity (general IHC practice). |
| Strong adipocyte signal (HPA: Not detected). | Possible cross-reactivity or endogenous activity (general IHC practice). | Check no-primary and detection controls (general IHC practice). |
| Diffuse background. | Blocking or wash conditions may contribute (general IHC practice). | Review blocking, washes and primary dilution (general IHC practice). |
| Weak cortical neuronal signal (HPA: High). | Detection may be insufficient (general IHC practice). | Check retrieval and detection controls (general IHC practice). |
| Only crisp plasma-membrane staining. | Unexpected for secretory vesicle SCG3 (UniProt Q8WXD2). | Compare with cytoplasmic positive controls (HPA tissue IHC; general IHC practice). |
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 bronchus respiratory epithelium as the negative tissue (HPA: Not detected in respiratory epithelial cells); on the pancreas slide, compare staining in neighboring non-endocrine cells with the negative controls rather than assuming those cells are SCG3-negative.
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 and a host-species- and immunoglobulin-matched control appropriate to the antibody’s clonality (standard IHC practice); use SCG3 knockout tissue or a validated immunizing-peptide block as a biological specificity control (standard IHC practice). For pancreatic sections, check endogenous peroxidase in chromogenic IHC and autofluorescence in IF with detection-only controls (standard IHC/IF practice).
⚠️Feasibility: A target-specific fixation window and the effect of antigen retrieval are unreported in the supplied evidence; compare retrieved and unretrieved paraffin sections during optimization (standard IHC practice). The selected catalog antibody has a rat-brain IHC(P) caption, but its fixative is unreported (PA1071 tissue-IHC caption). Vesicular staining is plausible (HPA: vesicles supported; UniProt Q8WXD2: secretory vesicles), but the supplied evidence does not establish whether frozen sections or IF are easier than paraffin IHC; assess pancreatic autofluorescence separately if using IF (standard 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, compartment, cellular context and controls before comparing signal intensity (UniProt Q8WXD2; HPA tissue IHC).
How should I optimize antigen retrieval when SCG3 staining is weak in paraffin sections?
Use citrate buffer at pH 6.0 for heat-induced retrieval at 95–98 °C for 20 min (page retrieval specification). Let sections cool in the buffer, then keep washes, antibody incubation and chromogenic development identical across a small retrieval series (standard IHC practice). Compare an untreated section with sections retrieved for 10, 20 and 30 min, looking for stronger cellular signal without diffuse background or tissue damage (standard IHC optimization). Score the same cell population in each section because SCG3 is associated with secretory vesicles and their membranes (UniProt Q8WXD2 localisation). If signal remains weak, test another retrieval buffer as a fallback and record its pH and heating time (standard IHC optimization).
Could fixation explain weak or uneven SCG3 staining?
Target-specific fixation sensitivity for SCG3 is unknown from the supplied evidence; the selected PA1071 rat brain IHC caption does not state a fixative (PA1071 tissue-IHC caption). If preparation records are available, compare sections with documented fixation histories under the same pH 6.0, 20 min retrieval condition (page retrieval specification; standard IHC practice). Check whether weak signal tracks with fixation history, section thickness or poorly preserved morphology before changing antibody concentration (standard IHC practice). Run a positive control alongside each comparison and assess signal in the expected cells rather than across the whole section (HPA tissue IHC; standard IHC practice). Report any fixation effect as an observation from that comparison, not an established SCG3 property.
What staining pattern should count as SCG3 localisation in IHC?
Assess SCG3 primarily as cellular cytoplasmic staining associated with secretory vesicles; it can also associate with the secretory granule membrane through cholesterol-enriched lipid rafts (UniProt Q8WXD2 localisation). In human tissue, HPA reports selective cytoplasmic expression in the CNS, pancreatic islets, adrenal medulla and some gastrointestinal cells (HPA tissue IHC). Compare staining within those cellular populations against adjacent cells and the counterstained morphology, recording granular versus diffuse signal separately (standard IHC interpretation). A crisp nuclear-only pattern warrants investigation because the supplied localisation evidence places SCG3 in vesicles rather than nuclei (UniProt Q8WXD2 localisation; HPA subcellular). Do not interpret membrane-adjacent staining as proof of a transmembrane protein: no transmembrane segment is annotated (UniProt Q8WXD2 topology).
How could SCG3 processing or isoforms affect antibody staining?
Check the antibody’s stated immunogen or mapped epitope against both annotated SCG3 isoforms before comparing staining between specimens (UniProt Q8WXD2 isoforms; standard IHC practice). The precursor has a signal peptide at residues 1–19, while the annotated mature chain spans 20–468; an epitope confined to the signal peptide may not report the mature protein (UniProt Q8WXD2 processing). Annotated glycosylation sites occur at residues 37, 216, 231 and 359, so document epitope location when evaluating possible accessibility differences (UniProt Q8WXD2 glycosylation). No epitope location is supplied for the catalog antibody here; avoid assigning a staining difference to a particular isoform or modification without epitope information and an independent comparison (supplied antibody evidence; standard IHC interpretation).
How can IF help check whether the IHC signal is in the expected cells?
Use IF as a separate comparison of cellular location, pairing SCG3 with a validated marker for the expected neuronal or pancreatic endocrine cell population (HPA tissue IHC; standard IF practice). Select a SCG3 fluorophore in a spectral channel with low tissue autofluorescence, then inspect unstained and single-label controls before judging overlap (standard IF practice). SCG3 is vesicular and has no annotated transmembrane segment, but the catalog antibody’s epitope side is unspecified (UniProt Q8WXD2 localisation and topology; supplied antibody evidence). Choose permeabilisation according to the mapped epitope’s accessibility, and compare permeabilised with nonpermeabilised preparations if that location remains uncertain (standard IF practice). Treat agreement in cell identity and punctate distribution as supporting context for chromogenic IHC, while evaluating the IHC controls independently (HPA subcellular; standard IHC/IF practice).
How do I reduce diffuse brown staining without losing SCG3 signal?
First compare the stained section with a no-primary control and inspect whether diffuse colour follows tissue edges, folds or damaged areas (standard chromogenic IHC practice). Include a peroxidase block before the detection reagent when using a peroxidase and DAB workflow, and keep development time identical across sections (standard chromogenic IHC practice). If background persists, titrate the primary antibody and blocking conditions in matched sections while retaining a clearly stained positive control (standard IHC optimization). Judge improvement in expected cells: HPA reports strong staining in cerebral cortical neurons and pancreatic endocrine cells, among other populations (HPA tissue IHC). Background outside those cells should not be rescued by extending DAB development, which can also intensify nonspecific signal (standard chromogenic IHC practice).
How should I quantify SCG3 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the anatomical region and cell class before scoring, because SCG3 staining is selective across cell populations in human tissues (HPA tissue IHC). For cellular intensity, record the percentage of cells at scores 0–3 and calculate an H-score as the sum of each percentage multiplied by its score (standard IHC scoring practice). If the question concerns abundance of stained cells, report percent positive among the relevant counterstained cells or positive-cell density per mm² of viable tissue (standard IHC quantification). Use the same threshold, retrieval condition, exposure and DAB development time for every section (page retrieval specification; standard IHC practice). State whether measurements reflect intensity per target cell or the proportion of target cells in the sampled region (standard IHC reporting).
How can I distinguish genuine SCG3 staining from an artefact?
A credible positive pattern matches the expected cell population and cytoplasmic or vesicle-associated distribution, with adequate morphology and a clean no-primary control (HPA tissue IHC; UniProt Q8WXD2 localisation; standard IHC practice). HPA reports high staining in cerebral cortical neurons and pancreatic endocrine cells, while adipocytes in adipose tissue are reported as not detected (HPA tissue IHC). Investigate dominant nuclear staining, isolated section-edge colour, necrotic regions or staining that appears equally in the no-primary control (UniProt Q8WXD2 localisation; standard IHC interpretation). Endogenous peroxidase can contribute brown signal in a peroxidase and DAB workflow, so assess the effect of the peroxidase block before calling a weak result positive (standard chromogenic IHC practice). Interpret discordant tissue results cautiously because secreted protein can complicate the relationship between tissue RNA and protein staining (HPA tissue IHC reliability description; UniProt Q8WXD2 localisation).
Boster reagents
Best SCG3 / Secretogranin-3 IHC Antibodies
PA1071 has real paraffin-section IHC images from rat brain and human rectal cancer (PA1071 IHC image captions). It lists human, mouse, and rat reactivity (PA1071 catalog reactivity).
Real IHC data
Anti-Secretogranin 3/SCG3 Antibody ®
Cat # PA1071
PA1071 is the only SKU listed; its IHC(P) images show rat brain and human rectal cancer tissue (PA1071 IHC image captions). It lists IHC and ICC applications and human, mouse, and rat reactivity; no IF image is supplied (PA1071 catalog applications/reactivity; IF image alts).
Which to pick: For tissue IHC, choose PA1071 based on its paraffin-section images from rat brain and human rectal cancer; the fixative is unreported (PA1071 IHC image captions). For IF/ICC, PA1071 lists ICC and 0.5–1 μg/ml, but has no IF image in the payload (PA1071 catalog applications/IF dilution; IF image alts). It is the only listed cross-species option, with human, mouse, and rat reactivity; its host is rabbit and clonality is unreported (PA1071 catalog reactivity/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 Cytoplasmic staining in CNS, islets and adrenal medulla (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); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image PA1071); Caveat: Secreted SCG3 may complicate tissue RNA–protein concordance (HPA tissue IHC); Isoform / epitope: 2 isoforms; signal peptide is cleaved; epitope impact unknown (UniProt); Regulation: Stimulus-dependent regulation unreported (UniProt). Evidence: UniProt Q8WXD2, HPA tissue IHC · Enhanced, HPA ICC-IF · vesicles., Datasheet PA1071, PMC8262226. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SCG3/immunohistochemistry-ihc-guide.