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CSGALNACT2 / Chondroitin sulfate N-acetylgalactosaminyltransferase 2 · IHC design guide
Design Immunohistochemistry for CSGALNACT2
This guide uses granular cytoplasmic staining as the observed IHC pattern (HPA tissue IHC) and Golgi membrane localization as a molecular expectation (UniProt). It highlights high staining in bronchial respiratory epithelium and the reported low concordance between staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CSGALNACT2 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 | Granular cytoplasm (HPA tissue IHC); Golgi membrane expected (UniProt) | |
| Staining pattern | Granular cytoplasmic staining in most tissues (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent across samples. (standard IHC practice; not target-specific) | |
| Caveat | Staining has low concordance with RNA expression (HPA tissue IHC) | |
| Regulation | No specific expression regulator annotated (UniProt) | |
| Isoform / epitope | 2 isoforms; epitope unknown (cytosolic 1–11, lumenal 33–542) (UniProt) |
Section 1
Recommended CSGALNACT2 IHC & IF Protocols
Compare the catalog antibody protocol with the published IHC protocol for ovarian cancer tissues (PMC11219422).
| Sample | Paraffin-embedded human breast carcinoma tissue; fixative not specified (datasheet A10939) |
| Fixation | Image fixative and duration unreported (datasheet A10939); 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-CSGALNACT2, 1:100-1:300 (datasheet A10939) |
| 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 | CSGALNACT2-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Granular cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 HIER at 95–98 °C for 20 min (page antigen retrieval); consider the published pressure-cooker retrieval if staining is weak (PMC11219422).
Section 2
What Is the Expected CSGALNACT2 Staining Pattern?
Expect granular cytoplasmic staining in many tissues, with high staining reported in selected glandular, epithelial, endothelial and neural cells (HPA: tissue IHC). CSGALNACT2 is anchored in the Golgi stack membrane, with residues 33–542 facing the lumen (UniProt Q8N6G5 topology). Treat the pattern as provisional: the tissue IHC assessment is Approved but reports low consistency between antibody staining and RNA expression (HPA: reliability).
| Granular cytoplasmic staining in adrenal or appendix glandular cells. | This fits the reported high staining in those cells (HPA: tissue IHC). Assess the granules within intact cells, alongside slide background and a matched negative control (general IHC practice). HPA's Approved rating supports use of the observed pattern, but its low RNA concordance limits how strongly staining alone identifies CSGALNACT2 (HPA: reliability). |
| Predominantly nuclear or surface-rim staining, with little granular cytoplasmic signal. | That distribution does not match the tissue IHC profile or Golgi stack membrane annotation (HPA: tissue IHC; UniProt Q8N6G5 localization). Check whether it persists in negative controls and with another validated antibody before assigning it to CSGALNACT2 (general IHC practice). A Golgi-associated protein can appear as cytoplasmic granules in tissue sections (UniProt Q8N6G5 localization; general IHC practice). |
| Strong staining confined to a cell population outside the reported high-staining groups. | Consider antibody cross-reactivity or endogenous chromogenic detection activity, especially if matched controls also stain (general IHC practice). Do not label an unlisted cell type negative: UniProt describes ubiquitous expression, and the supplied HPA tissue record provides no negative cell list (UniProt Q8N6G5 tissue specificity; HPA: tissue IHC). |
| Diffuse chromogen across tissue and surrounding background. | A field-wide haze cannot establish the reported intracellular granular pattern (HPA: tissue IHC). Uneven blocking, residual detection activity or excessive detection can produce background in chromogenic IHC (general IHC practice). Compare a no-primary control and tissue morphology before scoring individual cells (general IHC practice). |
| No signal in an intact adrenal or appendix section. | Both have reported high glandular-cell staining, so absence there calls for a run-level check (HPA: High in adrenal and appendix glandular cells). Verify tissue identity and the staining controls, then review retrieval, primary-antibody and detection steps (general IHC practice). A single negative slide does not establish absent CSGALNACT2 expression (HPA: reliability; general IHC practice). |
💡Expected CSGALNACT2 appearanceCall a section positive when identifiable cells show granular cytoplasmic staining, especially high staining in adrenal or appendix glandular cells (HPA: tissue IHC); isolated nuclear staining or field-wide haze without that pattern warrants control review (HPA: tissue IHC; general IHC practice).
| Cell and tissue context | HPA reports high staining in bronchial respiratory epithelium and selected endothelial, glial and glandular cells, but low staining in ovarian stroma, skeletal myocytes and adipocytes (HPA: tissue IHC). Interpret intensity by the cell type actually present in the section; the supplied record lists no negative tissue (HPA: tissue IHC). |
| Compartment and epitope | UniProt places residues 12–32 in the membrane, residues 1–11 on the cytoplasmic side and residues 33–542 in the lumen (UniProt Q8N6G5 topology). This supports a Golgi-associated intracellular interpretation but does not identify the antibody epitope or establish a target-specific retrieval requirement (UniProt Q8N6G5 topology). |
| Strength of IHC evidence | The tissue profile is Approved and described as granular cytoplasmic expression in most tissues, while antibody staining has low consistency with RNA expression (HPA: tissue IHC reliability). Use morphology and controls when scoring an unexpected positive; neither the rating nor RNA enrichment alone verifies its specificity (HPA: tissue IHC reliability; general IHC practice). |
| IF/ICC: what compartment is reported? | HPA's approved ICC-IF location is endoplasmic reticulum, whereas UniProt annotates the Golgi stack membrane (HPA: subcellular ICC-IF; UniProt Q8N6G5 localization). Record that difference when comparing assays; the tissue IHC profile alone cannot resolve it (HPA: tissue IHC; HPA: subcellular ICC-IF). |
| Isoforms and processing | UniProt lists 2 isoforms, a full-length chain of residues 1–542 and no annotated signal peptide or propeptide (UniProt Q8N6G5). These annotations do not establish isoform-specific staining or antibody recognition, so do not infer either from chromogenic intensity alone (UniProt Q8N6G5; general IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| No staining in a reported high-staining glandular control. | A failed staining run, unsuitable section or missed target signal is possible (general IHC practice). | Confirm adrenal or appendix glandular cells are present (HPA: tissue IHC); check run controls, retrieval, primary-antibody handling and detection in that order (general IHC practice). |
| Only nuclei show strong chromogen. | The pattern conflicts with granular cytoplasmic IHC and Golgi membrane localization (HPA: tissue IHC; UniProt Q8N6G5). | Inspect the no-primary control and repeat with a validated independent antibody where available; score nuclear-only staining as unresolved (general IHC practice). |
| The whole section has brown haze. | Background from detection, blocking or washing can obscure intracellular granules (general IHC practice). | Compare a no-primary control, review blocking and washes, and adjust detection conditions before scoring cells (general IHC practice). |
| Signal appears mainly in unexpected cells. | Cross-reactivity or endogenous chromogenic activity is possible; an unlisted cell population is not a documented negative (HPA: tissue IHC; general IHC practice). | Check cell identity, no-primary and endogenous-activity controls, then seek independent antibody support before calling the signal specific (general IHC practice). |
| A low-staining reference looks as intense as the glandular control. | Low staining is reported for ovarian stroma, myocytes and adipocytes, while adrenal and appendix glandular cells are high (HPA: tissue IHC). | Verify which cells carry signal and compare slides processed in the same run; investigate background before interpreting the apparent intensity reversal (general IHC practice). |
| IHC and IF images suggest different organelles. | UniProt annotates Golgi stack membrane localization; HPA reports approved endoplasmic reticulum localization by ICC-IF (UniProt Q8N6G5; HPA: subcellular ICC-IF). | Document assay and cell context separately and avoid forcing an organelle call from chromogenic tissue sections alone (general IHC practice). |
Experiment evidence
IHC & IF images showing CSGALNACT2 staining
A10939 · IHCImmunohistochemistry analysis of paraffin-embedded human breast carcinoma tissue, using CSGALNACT2 Antibody. The picture on the right is blo
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000169826-CSGALNACT2/tissue/cerebral+cortex#imid_7876344
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000169826-CSGALNACT2/tissue/colon#imid_7872886
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000169826-CSGALNACT2/tissue/liver#imid_7872895
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000169826-CSGALNACT2/tissue/kidney#imid_7872896
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA031540; green = CSGALNACT2, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA031540; green = CSGALNACT2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CSGALNACT2 IHC & IF
🧪Run bronchus first and score respiratory epithelial cells, which HPA rates High (HPA: bronchus). HPA detects CSGALNACT2 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls, and treat cells showing counterstain alone on the positive slide as background references rather than validated target-negative cells (HPA: no negative rows).
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: None in HPA: CSGALNACT2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CSGALNACT2 in A-431, U-251MG, U2OS, with annotated localisation: Endoplasmic reticulum (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide, a host-species- and clonality-matched isotype control, and a knockout specimen or peptide-blocked primary as a biological specificity control; the selected IHC caption reports peptide blocking (A10939 tissue-IHC caption). For chromogenic bronchus IHC, block endogenous peroxidase and inspect inflammatory cells for residual background (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and retrieval dependency are unreported in the supplied evidence; the paraffin-section caption does not state a fixative (A10939 tissue-IHC caption). The evidence does not establish whether frozen sections or IF/ICC would be easier, although HPA lists ICC-IF images for A-431, U-251MG and U2OS (HPA: subcellular). In bronchus, endogenous peroxidase in inflammatory cells can complicate chromogenic interpretation (standard IHC practice).
HPA tissue IHC evidence for CSGALNACT2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in molecular layer | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: CSGALNACT2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced CSGALNACT2 IHC Tips
Troubleshoot CSGALNACT2 staining by checking retrieval, compartment, cell identity and controls before interpreting chromogenic IHC signal.
What retrieval should I try when CSGALNACT2 staining is weak in paraffin sections?
Start with citrate pH 6.0 heat-induced epitope retrieval at 95–98 °C for 20 min (page retrieval rule). Let sections cool in buffer, then compare staining with a matched section processed without retrieval; this checks whether heating improves signal in your material (standard IHC practice). Keep antibody concentration and chromogen development time identical across sections so retrieval is the variable being tested (standard IHC practice). If staining remains weak, test another retrieval buffer or pH on adjacent sections and assess tissue preservation alongside signal (standard IHC practice). Judge improvement by a reproducible granular cytoplasmic pattern rather than stronger diffuse staining alone (HPA: tissue IHC profile).
How should I assess whether fixation is limiting CSGALNACT2 IHC?
Target-specific fixation sensitivity for CSGALNACT2 is unknown from the supplied evidence (evidence payload: no target-specific fixation comparison). The catalog image shows paraffin-embedded human breast carcinoma tissue, but its caption does not state the fixative (catalog caption: A10939). Record the actual fixative and processing history for each specimen, then compare similarly processed sections before attributing weak staining to fixation (standard IHC practice). Include a tissue control with an established staining pattern in the same run, and inspect morphology for processing damage (standard IHC practice). Do not treat the catalog image as evidence that a particular fixation time preserves this epitope (catalog caption: A10939).
Where should convincing CSGALNACT2 staining appear?
Look for granular cytoplasmic staining in tissue sections, the pattern reported across most tissues by HPA (HPA: tissue IHC profile). A Golgi-associated pattern is biologically plausible because CSGALNACT2 is annotated at the Golgi stack membrane (UniProt Q8N6G5: subcellular location). HPA separately reports an approved endoplasmic reticulum location from ICC/IF, so these sources do not establish one identical pattern across methods (HPA: subcellular summary; UniProt Q8N6G5: subcellular location). Compare signal within intact cells against adjacent background and note whether staining is punctate, diffuse or restricted to tissue edges (standard IHC practice). Treat isolated nuclear or extracellular chromogen as requiring further validation before calling it target staining (standard IHC practice).
Can this antibody distinguish CSGALNACT2 isoforms or reveal epitope accessibility?
CSGALNACT2 has 2 annotated isoforms, but the supplied antibody caption does not define an isoform-specific epitope (UniProt Q8N6G5: isoforms; catalog caption: A10939). The protein spans the membrane at residues 12–32, with residues 1–11 cytoplasmic and 33–542 lumenal (UniProt Q8N6G5: topology). It also has annotated glycosylation sites at residues 41 and 333, which should inform epitope review without proving altered staining (UniProt Q8N6G5: glycosylation). Check the antibody's documented immunogen against each isoform before claiming isoform selectivity, and compare retrieval conditions when epitope accessibility is uncertain (standard IHC practice). Peptide blocking in the catalog image supports competition by that peptide, but does not establish isoform discrimination (catalog caption: A10939).
How should I investigate CSGALNACT2 localisation by multiplex IF?
Pair CSGALNACT2 with a marker identifying the cell type under study, such as a glandular cell marker when examining glandular tissue (HPA: high staining in adrenal and endometrial glandular cells; standard IF practice). Choose spectrally separated fluorophores and consider a red or far-red channel for CSGALNACT2 after checking unstained tissue autofluorescence (standard IF practice). For an antibody against the lumenal region at residues 33–542, optimise permeabilisation to expose intracellular membrane compartments without losing structure (UniProt Q8N6G5: topology; standard IF practice). If its epitope is cytoplasmic instead, assess access to residues 1–11 under the same conditions (UniProt Q8N6G5: topology). Compare the result with HPA's endoplasmic reticulum report while recording the IHC tissue pattern separately (HPA: subcellular summary and tissue IHC profile).
How can I separate background chromogen from CSGALNACT2 signal?
Run a no-primary control and inspect areas with heavy pigment or damaged tissue before setting the chromogen development time (standard IHC practice). Include a peroxidase block for enzyme-based detection and match blocking, washes and detection reagents across control and test sections (standard IHC practice). Diffuse staining over stroma or along section edges deserves scrutiny when the reported tissue pattern is granular cytoplasmic staining (HPA: tissue IHC profile; standard IHC practice). The catalog image includes a synthesized-peptide blocking comparison in paraffin-embedded human breast carcinoma, which can help assess antibody-dependent signal in that example (catalog caption: A10939). Interpret peptide competition together with localisation and control staining, since competition alone does not identify every stained cell or compartment (standard IHC practice).
What should I score when comparing CSGALNACT2 IHC across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and scoring compartment before comparing sections, using granular cytoplasmic staining as the tissue pattern of interest (HPA: tissue IHC profile; standard IHC practice). Record the percentage of positive cells and staining intensity, or calculate an H-score from intensity categories using the same thresholds for every slide (standard IHC practice). For spatial analyses, report positive-cell density per mm² of viable tissue or the relevant annotated compartment (standard IHC practice). Normalise counts to the number of evaluable cells or viable area, and keep retrieval, imaging and chromogen development consistent (standard IHC practice). Record cell type alongside the score because HPA reports different staining levels among tissue cell populations (HPA: tissue IHC profile).
When should apparent CSGALNACT2 positivity be treated as artefact?
Prioritise reproducible granular cytoplasmic staining in intact cells when assessing a positive IHC result (HPA: tissue IHC profile; standard IHC practice). Check cell identity against the tissue context: HPA reports high staining in several glandular and endothelial populations but low staining in ovarian stroma cells, myocytes and adipocytes (HPA: tissue IHC profile). Isolated nuclear, extracellular, edge-restricted or necrotic-area staining needs control review before assignment to CSGALNACT2 (standard IHC practice). Compare suspicious chromogen with the no-primary and peroxidase-block controls to assess detection background and endogenous enzyme activity (standard IHC practice). HPA rates its tissue staining approved while reporting low consistency with RNA expression, so interpret a single stain with that limitation in mind (HPA: reliability description).
Boster reagents
Best CSGALNACT2 / Chondroitin sulfate N-acetylgalactosaminyltransferase 2 IHC Antibodies
A10939 is listed for human and mouse IHC and IF (catalog: applications and reactivity). Its IHC figure shows paraffin-embedded human breast carcinoma tissue (IHC image caption).
Real IHC data
Anti-CsGalNAcT-2 Antibody
Cat # A10939
A10939 will render with a human breast carcinoma paraffin-section IHC figure and a peptide-blocked comparison (IHC image caption). It lists IHC and IF for human and mouse, but supplies no IF figure (catalog: applications and reactivity; IF image alts: empty).
Which to pick: Choose A10939 for tissue IHC because its own figure shows paraffin-embedded human breast carcinoma tissue; the fixative is unreported (IHC image caption). For IF/ICC, A10939 lists IF but does not list ICC or supply an IF figure (catalog: applications; IF image alts: empty). For cross-species work, A10939 lists human and mouse reactivity; its host is rabbit and its clonality is unspecified (catalog: reactivity, host, clone).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q8N6G5 (CGAT2_HUMAN, Chondroitin sulfate N-acetylgalactosaminyltransferase 2).
- Human Protein Atlas. CSGALNACT2 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. CSGALNACT2 subcellular location (ICC-IF): Localized to the endoplasmic reticulum..
- Human Protein Atlas. CSGALNACT2 antibody validation summary (1 antibodies).
- CSGALNACT2 restricts ovarian cancer migration and invasion by modulating MAPK/ERK pathway through DUSP1. Cellular oncology (Dordrecht, Netherlands) 2024 — PMC11219422.
- PubMed PMID:12446672 — UniProt-cited evidence.
- PubMed PMID:12433924 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CSGALNACT2 (Chondroitin sulfate N-acetylgalactosaminyltransferase 2). Expected localisation Granular cytoplasm (HPA tissue IHC); Golgi membrane expected (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A10939 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human breast carcinoma tissue; fixative not specified (datasheet A10939); 2. Fixation: Image fixative and duration unreported (datasheet A10939); 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-CSGALNACT2, 1:100-1:300 (datasheet A10939); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep paraffin-section fixation consistent across samples. (standard IHC practice; not target-specific); Caveat: Staining has low concordance with RNA expression (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope unknown (cytosolic 1–11, lumenal 33–542) (UniProt); Regulation: No specific expression regulator annotated (UniProt). Evidence: UniProt Q8N6G5, HPA tissue IHC · Approved, HPA ICC-IF · endoplasmic reticulum., Datasheet A10939, PMC11219422. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CSGALNACT2/immunohistochemistry-ihc-guide.