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CHPF / Chondroitin polymerizing factor, non-catalytic subunit · IHC design guide
Design Immunohistochemistry for CHPF
Plan CHPF chromogenic IHC in paraffin sections around granular cytoplasmic and membranous staining (HPA tissue IHC). Start with the catalog antibody’s 1:100–1:300 IHC dilution range (datasheet), using glandular cells as a positive reference and adipocytes as a negative reference (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CHPF 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 cytoplasmic and membranous staining (HPA tissue IHC) | |
| Staining pattern | Granular cytoplasm and membranes in glandular cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Antibody staining has medium consistency with RNA expression (HPA tissue IHC) | |
| Regulation | No specific expression regulator reported (UniProt) | |
| Isoform / epitope | 3 isoforms; epitope map unknown; cytosolic versus luminal side matters (UniProt) |
Section 1
Recommended CHPF IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet) with three published CHPF IHC protocols (PMC8002199; PMC6499445; PMC8464597).
| Sample | Paraffin-embedded human cervix carcinoma tissue; fixative not specified (datasheet A30610) |
| Fixation | Image fixative and duration unreported (datasheet A30610); 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-CHPF, 1:100 - 1:300 (datasheet A30610) |
| 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 | CHPF-positive staining in glandular cells of appendix (HPA tissue IHC: Medium). HPA tissue profile: Granular cytoplasmic and membranous expression in several tissues. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 HIER at 95–98 °C for 20 min (page retrieval rule).
Section 2
What Is the Expected CHPF Staining Pattern?
CHPF is annotated at the Golgi stack membrane, with cytosolic and mitochondrial locations; its single membrane span is at residues 16–34 (UniProt Q8IZ52 topology and subcellular location). In tissue IHC, expect granular cytoplasmic and membranous staining in selected cells, including glandular and respiratory epithelial cells (HPA tissue IHC). HPA rates the tissue pattern Approved, with medium consistency between staining and RNA data (HPA tissue IHC).
| Granular cytoplasmic or membranous signal in glandular cells of appendix, breast, cervix or duodenum (HPA tissue IHC). | This matches the reported medium staining in those cells (HPA tissue IHC). Use cell identity and compartment together when judging a positive section; neither feature alone establishes antibody specificity. |
| Granular cytoplasmic or membranous signal in bronchial respiratory epithelial cells or caudate neuronal cells (HPA tissue IHC). | Both are reported at medium intensity (HPA tissue IHC). CHPF has multiple annotated locations (UniProt Q8IZ52 subcellular location), so a tissue section need not resolve a single Golgi structure. |
| Predominantly nuclear staining, with little corresponding cytoplasmic or membranous signal. | A dominant nuclear pattern conflicts with the reported tissue pattern (HPA tissue IHC) and annotated locations (UniProt Q8IZ52 subcellular location). Check the control section and detection background before calling it CHPF. |
| Strong signal in adipocytes or oral mucosal squamous epithelial cells, especially if control tissue stains broadly. | Those cell populations are reported as not detected (HPA tissue IHC). Consider cross-reactivity or endogenous detection activity; a single discordant section does not identify which is responsible. |
| Uniform haze across cells and extracellular areas, or no signal in appendix glandular cells. | Diffuse haze lacks the reported granular cellular pattern; appendix glandular cells are reported at medium intensity (HPA tissue IHC). Assess background and assay performance separately before interpreting absence as biology. |
💡Expected CHPF appearanceCall a convincing positive when selected glandular, respiratory epithelial or neuronal cells show medium granular cytoplasmic or membranous staining (HPA tissue IHC); broad nuclear or extracellular staining is discordant with that pattern (HPA tissue IHC).
| Cell population and tissue | HPA reports medium signal in several specified cell populations but not detected signal in others (HPA tissue IHC). Score the named cell type within each section, rather than assigning one expectation to the whole organ. |
| Membrane topology and antibody epitope | CHPF has one membrane span at residues 16–34, with residues 1–15 cytoplasmic and 35–775 luminal (UniProt Q8IZ52 topology). The supplied record does not locate the antibody epitope, so it cannot predict epitope-specific retrieval or permeabilisation needs. |
| Isoforms and glycosylation | UniProt lists 3 isoforms and glycosylation sites at residues 138 and 361 (UniProt Q8IZ52). Antibody recognition of individual isoforms and any effect of glycosylation on staining are unspecified; avoid attributing pattern differences to either. |
| Evidence across assay types | Tissue IHC is Approved with medium staining–RNA consistency (HPA tissue IHC); HPA ICC-IF reports supported cytosol plus approved vesicle and centrosome locations (HPA subcellular). IF/ICC expectation? Consult its own guide: these cultured-cell observations do not establish a paraffin-section staining pattern. |
| RNA and protein observations | UniProt describes broad expression, including skeletal muscle (UniProt Q8IZ52 tissue specificity), while HPA reports skeletal myocytes as not detected by tissue IHC (HPA tissue IHC). Treat that difference as assay-context evidence, not proof of an IHC-positive myocyte. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in appendix glandular cells. | The expected medium signal is missing (HPA tissue IHC); the section alone cannot distinguish assay failure from sample variation. | Check a matched positive section, antibody and detection controls, then review the general IHC workflow, including retrieval, primary-antibody incubation and chromogen development (general IHC practice). |
| Uniform brown haze obscures cellular boundaries. | This differs from granular cytoplasmic and membranous expression (HPA tissue IHC); nonspecific binding or detection background is possible (general IHC practice). | Compare a primary-antibody omission control; review blocking, washes and detection timing (general IHC practice). Re-score only where cell boundaries and subcellular signal remain interpretable. |
| Strong nuclear staining dominates the section. | A dominant nuclear pattern lacks support from the tissue profile (HPA tissue IHC) or annotated CHPF locations (UniProt Q8IZ52 subcellular location). | Inspect a known-positive tissue alongside the test section and compare omission-control staining (general IHC practice). Do not score nuclear-only signal as a confirmed CHPF positive. |
| Adipocytes or oral mucosal squamous cells stain strongly. | HPA reports these cells as not detected (HPA tissue IHC); cross-reactivity or endogenous detection activity may account for discordant signal. | Compare primary-antibody omission and detection controls, then recheck cell identity and staining distribution (general IHC practice). Investigate persistent signal before assigning CHPF expression. |
| Skeletal myocytes are negative despite broad expression reported by UniProt. | HPA reports skeletal myocytes as not detected by tissue IHC (HPA tissue IHC), whereas UniProt lists skeletal muscle among highly expressed tissues (UniProt Q8IZ52 tissue specificity). | Use an HPA medium cell population as the IHC performance reference (HPA tissue IHC). Record the myocyte result separately; do not infer an antigen-retrieval or fixation defect from this difference. |
| Only diffuse cytosolic signal is visible and a discrete Golgi pattern cannot be resolved. | HPA describes granular cytoplasmic and membranous tissue staining (HPA tissue IHC); UniProt also annotates cytosol and Golgi stack membrane (UniProt Q8IZ52 subcellular location). | Assess granularity, cell specificity and control background at the section's available resolution (general IHC practice). Reserve a positive call for a pattern consistent with the tissue IHC profile (HPA tissue IHC). |
Experiment evidence
IHC & IF images showing CHPF staining
A30610 · IHCImmunohistochemistry analysis of paraffin-embedded human cervix carcinoma tissue, using CHSY2 Antibody. The picture on the right is blocked
A30610 · IFImmunofluorescence analysis of MCF7 cells, using CHSY2 Antibody. The picture on the right is blocked with the synthesized peptide.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000123989-CHPF/tissue/cerebral+cortex#imid_8274755
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000123989-CHPF/tissue/colon#imid_8271817
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000123989-CHPF/tissue/liver#imid_8271802
HPA · PancreasHuman Protein Atlas IHC, Pancreas. Source: https://www.proteinatlas.org/ENSG00000123989-CHPF/tissue/pancreas#imid_8271769
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA035123; green = CHPF, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA035123; green = CHPF, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CHPF IHC & IF
🧪Run appendix first: its glandular cells should stain (HPA: Appendix glandular cells, Medium). Use adipose tissue as the negative comparator (HPA: adipocytes, Not detected); assess adjacent nonglandular cells on the appendix slide as potential internal background, since their CHPF status is unreported (HPA: Appendix row specifies glandular cells only).
Positive control tissue: Appendix (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CHPF in A-431, U-251MG, U2OS, with annotated localisation: Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) slide, a concentration-matched isotype control appropriate to the primary antibody’s host species and clonality, and CHPF knockout material or a cognate-peptide block as a biological specificity control (standard IHC practice; selected SKU caption: peptide-blocked image). Quench endogenous peroxidase on the appendix section and compare staining with the no-primary slide before scoring glandular cells (standard chromogenic IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A30610 paraffin-section caption does not state a fixative (selected SKU caption: fixative unreported). CHPF-specific antigen-retrieval dependence is unreported; optimize retrieval empirically for the IHC-validated antibody (supplied evidence: no retrieval conditions). The supplied evidence does not establish that frozen sections or IF are easier, or identify an appendix-specific artefact; ICC-IF images are available for A-431, U-251MG and U2OS if IF localization is assessed separately (HPA: subcellular ICC-IF images).
HPA tissue IHC evidence for CHPF
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium 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 |
|---|---|---|---|---|
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Caudate | Neuronal cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Hippocampus | Glial cells | Not detected | Protein (IHC) | HPA → |
| Oral mucosa | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CHPF IHC Tips
Troubleshoot CHPF staining in paraffin sections by checking retrieval, compartment, controls and scoring together (UniProt Q8IZ52; HPA tissue IHC).
How should I retrieve CHPF when staining is weak in paraffin sections?
Start CHPF retrieval in citrate buffer at pH 6.0, 95–98 °C for 20 min (page retrieval setting). Let sections cool consistently, then compare staining in a reference section and a no-primary control before changing the antibody concentration (standard IHC practice). If staining remains weak, test a longer citrate incubation or an EDTA-based alkaline retrieval on adjacent sections, changing only one condition at a time (standard IHC practice). Assess whether stronger retrieval improves the expected granular cytoplasmic and membranous pattern without damaging morphology or raising background (HPA tissue IHC; standard IHC practice).
Can fixation account for absent CHPF staining?
Target-specific sensitivity of CHPF to fixation is unknown from the supplied evidence; the selected product caption identifies paraffin-embedded cervix carcinoma but does not state its fixative (A30610 caption). Record the fixative and fixation duration for every specimen, and compare sections processed under the same conditions before attributing a difference to CHPF abundance (standard IHC practice). If staining fails, inspect tissue preservation and run a known staining reference through the same citrate pH 6.0, 95–98 °C, 20 min retrieval cycle (page retrieval setting; standard IHC practice). Do not infer fixation tolerance from the reported tissue patterns or protein topology (HPA tissue IHC; UniProt Q8IZ52 topology).
Which compartments should show convincing CHPF staining?
In tissue sections, look for a granular cytoplasmic and membranous pattern, while checking the stained cell type against the tissue context (HPA tissue IHC). CHPF is annotated at the Golgi stack membrane and also in cytosol and mitochondria, including the mitochondrial matrix (UniProt Q8IZ52 subcellular annotation). Its single transmembrane segment spans residues 16–34, with residues 35–775 on the lumenal side (UniProt Q8IZ52 topology). A diffuse nuclear-only signal therefore warrants a specificity check using a no-primary control and an adjacent section processed identically (UniProt Q8IZ52 subcellular annotation; standard IHC practice).
Could epitope position or CHPF isoforms change my IHC result?
CHPF has 3 annotated isoforms, but the supplied evidence does not map this antibody’s epitope to them (UniProt Q8IZ52 isoforms; A30610 caption). The precursor has one membrane span at residues 16–34, a short cytoplasmic segment at 1–15, and a lumenal region at 35–775 (UniProt Q8IZ52 topology). Glycosylation is annotated at residues 138 and 361; whether either site affects this antibody’s staining is unknown (UniProt Q8IZ52 glycosylation; A30610 caption). Obtain the immunogen or epitope information before interpreting discordant staining as isoform-specific, and compare with an independently validated epitope when available (standard IHC practice).
How can I check CHPF localisation with multiplex IF?
For a separate IF experiment, pair CHPF with a marker identifying the cell population being examined, such as glandular cells in cervix, and include single-label controls (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores after checking tissue autofluorescence in an unstained section; reserve the cleaner channel for a weak CHPF signal (standard IF practice). Because residues 35–775 are lumenal while residues 1–15 are cytoplasmic, choose and validate permeabilisation against the antibody’s mapped epitope (UniProt Q8IZ52 topology; standard IF practice). The supplied evidence does not establish this antibody’s IF fixation or permeabilisation conditions, so optimise those conditions with controls (A30610 caption; standard IF practice).
What should I change if chromogenic CHPF staining is widespread?
First compare the section with a no-primary control to locate background from the detection system, and check whether pigment or precipitate persists outside cells (standard IHC practice). For peroxidase-based detection, block endogenous peroxidase before DAB development and titrate the primary antibody and development time on adjacent sections (standard IHC practice). CHPF tissue staining is described as granular cytoplasmic and membranous, so uniform staining across nuclei and extracellular material deserves scrutiny (HPA tissue IHC). The A30610 caption reports peptide blocking in a paraffin-embedded cervix carcinoma image, but that comparison alone does not establish the cause of staining in other specimens (A30610 caption).
How should I quantify CHPF across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because the reported tissue pattern includes granular cytoplasmic and membranous staining (HPA tissue IHC; standard IHC practice). For a defined cell population, record the percentage positive and intensity categories 0–3, then calculate an H-score on a 0–300 scale (standard IHC practice). If spatial distribution is central, report positive-cell density per mm² of viable, annotated tissue instead (standard IHC practice). Normalise counts to the same eligible cell population or viable tissue area, and use matched retrieval, detection and imaging conditions across specimens (standard IHC practice).
When is an apparent CHPF-positive focus likely to be artefactual?
Judge a focus against the expected granular cytoplasmic and membranous tissue pattern, while allowing for the annotated Golgi, cytosolic and mitochondrial locations (HPA tissue IHC; UniProt Q8IZ52 subcellular annotation). Check whether the stained cells fit the specimen: medium glandular-cell staining is reported in cervix, whereas oral mucosal squamous epithelial cells were reported as not detected (HPA tissue IHC). Staining confined to section edges, necrotic areas or regions positive in a no-primary control needs investigation for processing or detection artefact (standard IHC practice). In peroxidase/DAB IHC, repeat the peroxidase block and compare an adjacent controlled section before assigning such signal to CHPF (standard IHC practice).
Boster reagents
Best CHPF / Chondroitin polymerizing factor, non-catalytic subunit IHC Antibodies
A30610 has IHC data from paraffin-embedded human cervix carcinoma tissue (IHC image caption) and IF data from MCF7 cells (IF image caption); catalog reactivity includes human, mouse, and rat (catalog).
Real IHC data
Anti-CHSY2 CHPF Antibody
Cat # A30610
A30610 will render with its IHC image from paraffin-embedded human cervix carcinoma tissue (IHC image caption). Its IF image shows MCF7 cells (IF image caption), while IHC, IF, and ICC are listed applications (catalog).
Which to pick: For tissue IHC, choose A30610; its own image documents paraffin-embedded human cervix carcinoma tissue, with the fixative unreported (IHC image caption). For IF/ICC, A30610 has an IF image in MCF7 cells (IF image caption) and lists ICC as an application (catalog). For cross-species work, this rabbit polyclonal antibody lists human, mouse, and rat reactivity (catalog); the supplied IHC image documents human tissue only (IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q8IZ52 (CHSS2_HUMAN, Chondroitin polymerizing factor, non-catalytic subunit).
- Human Protein Atlas. CHPF tissue IHC expression (reliability: Approved).
- Human Protein Atlas. CHPF subcellular location (ICC-IF): Mainly localized to the cytosol. In addition localized to vesicles and centrosome..
- Human Protein Atlas. CHPF antibody validation summary (1 antibodies).
- CHPF Regulates the Aggressive Phenotypes of Hepatocellular Carcinoma Cells via the Modulation of the Decorin and TGF-β Pathways. Cancers 2021 — PMC8002199.
- Knockdown of CHPF suppresses cell progression of non-small-cell lung cancer. Cancer management and research 2019 — PMC6499445.
- The HNF4A-CHPF pathway promotes proliferation and invasion through interactions with MAD1L1 in glioma. Aging 2023 — PMC10637790.
- CHPF promotes gastric cancer tumorigenesis through the activation of E2F1. Cell death & disease 2021 — PMC8464597.
- PubMed PMID:12716890 — UniProt-cited evidence.
- PubMed PMID:12761225 — UniProt-cited evidence.
- PubMed PMID:12975309 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CHPF (Chondroitin polymerizing factor, non-catalytic subunit). Expected localisation Granular cytoplasmic and membranous staining (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A30610 at 1:100 - 1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human cervix carcinoma tissue; fixative not specified (datasheet A30610); 2. Fixation: Image fixative and duration unreported (datasheet A30610); 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-CHPF, 1:100 - 1:300 (datasheet A30610); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Antibody staining has medium consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 3 isoforms; epitope map unknown; cytosolic versus luminal side matters (UniProt); Regulation: No specific expression regulator reported (UniProt). Evidence: UniProt Q8IZ52, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the cytosol. In addition localized to vesicles…, Datasheet A30610, PMC8002199, PMC6499445. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CHPF/immunohistochemistry-ihc-guide.