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CHPF / Chondroitin polymerizing factor, non-catalytic subunit · IHC design guide
Design Immunohistochemistry for CHPF
Plan CHPF paraffin IHC around granular cytoplasmic and membranous staining in several tissues (HPA tissue IHC). The catalog antibody has an IHC dilution of 1:100–1:300 (datasheet); HPA reports medium staining in several glandular cell populations and no detected staining in skeletal myocytes (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 | Glandular cells: granular cytoplasmic and membranous signal (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 | Skeletal myocytes: undetected despite high muscle expression (HPA tissue IHC; UniProt) | |
| Regulation | Stimulus-specific regulation not reported (UniProt) | |
| Isoform / epitope | 3 isoforms; check cytosolic vs lumenal epitope (UniProt) |
Section 1
Recommended CHPF IHC & IF Protocols
The catalog antibody protocol is followed by three published CHPF IHC protocols for paraffin-embedded tissues (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 retrieval at 95–98 °C for 20 min for paraffin sections (page retrieval rule); adjust using the published conditions where specified (PMC6499445; PMC8464597).
Section 2
What Is the Expected CHPF Staining Pattern?
CHPF is annotated at the Golgi stack membrane, in the cytosol and in mitochondria; its single membrane segment spans residues 16–34, with residues 35–775 lumenal (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 staining in appendix, breast or duodenal glandular cells, or bronchial respiratory epithelial cells (HPA tissue IHC). | This matches HPA's reported pattern and medium staining in those cell types (HPA tissue IHC). Assess the named cells within the section: UniProt describes broad tissue expression, but that does not mean every cell should stain (UniProt Q8IZ52 tissue specificity; HPA tissue IHC). |
| Predominantly nuclear staining, with little cytoplasmic or membranous signal. | An isolated nuclear pattern falls outside the reported tissue pattern and annotated locations; treat it as possible artefact and review the controls (HPA tissue IHC; UniProt Q8IZ52 subcellular location). Diffuse cytosolic signal alone needs context because cytosol is annotated by both sources (UniProt Q8IZ52; HPA subcellular ICC-IF). |
| Strong staining in adipocytes, skeletal myocytes or oral squamous epithelial cells. | Those cell types were not detected in the supplied HPA tissue survey (HPA tissue IHC). Consider cross-reactivity or endogenous detection activity, then compare neighboring cells and controls; a single unexpected section does not establish that CHPF is absent from every specimen of that tissue (general IHC practice; HPA tissue IHC). |
| A uniform haze covers cells, stroma and empty regions, obscuring cellular boundaries. | This does not resolve the granular cytoplasmic and membranous pattern reported for CHPF (HPA tissue IHC). Background can arise from nonspecific antibody binding or the detection system; a no-primary control helps identify detection-related staining (general IHC practice). |
| No signal in appendix glandular cells or bronchial respiratory epithelium despite interpretable tissue morphology. | HPA reports medium staining in these cells, so the result warrants a technical check (HPA tissue IHC). Confirm the cell type and inspect positive and no-primary controls before interpreting the section as biologically negative (general IHC practice). |
💡Expected CHPF appearanceCall a result positive when the appropriate glandular or respiratory epithelial cells show discernible medium granular cytoplasmic or membranous staining (HPA tissue IHC); isolated nuclear color or uniform section-wide haze is suspect because it does not match that reported pattern (HPA tissue IHC; general IHC practice).
| Compartment and epitope context | CHPF has one membrane span at residues 16–34 and a lumenal region at 35–775 (UniProt Q8IZ52 topology). This supports a membrane-associated interpretation, but no antibody epitope is supplied, so epitope accessibility or an optimal retrieval condition cannot be inferred. |
| Tissue and cell selection | HPA reports medium staining in selected glandular, respiratory epithelial, neuronal and endothelial cells, while several sampled cell types were not detected (HPA tissue IHC). Select a comparator by its documented cell type, then score that cell type rather than the whole tissue (general IHC practice). |
| Strength of evidence | The tissue IHC pattern is Approved, with medium staining–RNA consistency; antibody HPA035123 has IHC Approved status (HPA tissue IHC; HPA antibodies). These ratings support an expected pattern, but the supplied antibody record does not report an Enhanced IHC validation status (HPA antibodies). |
| What should IF/ICC show? | HPA reports mainly cytosolic CHPF, with additional vesicle and centrosome localization in ICC-IF; cytosol is supported, while vesicles and centrosome are approved (HPA subcellular ICC-IF). These cell-image findings can inform interpretation, but tissue IHC remains the primary application here (HPA tissue IHC; HPA subcellular ICC-IF). |
| Situation | Likely cause | Next action |
|---|---|---|
| The expected glandular or respiratory epithelial cells have no visible chromogen (HPA tissue IHC). | The sampled cells may be misidentified, or the IHC workflow may have failed; HPA reports medium signal in the specified cells (HPA tissue IHC; general IHC practice). | Check morphology and a documented positive tissue alongside the no-primary control; then review the antibody's IHC-P staining and detection conditions (general IHC practice). |
| Staining appears exclusively nuclear. | Nuclear-only staining conflicts with the reported granular cytoplasmic and membranous tissue pattern and annotated locations (HPA tissue IHC; UniProt Q8IZ52 subcellular location). | Compare the no-primary control and the documented positive cell type; treat persistent isolated nuclear staining as unconfirmed until antibody specificity is assessed (general IHC practice). |
| Adipocytes, skeletal myocytes or oral squamous epithelial cells stain strongly. | HPA did not detect CHPF in those sampled cell types; nonspecific binding or endogenous detection activity is possible (HPA tissue IHC; general IHC practice). | Run a no-primary control and inspect whether the signal follows the cells or the detection reagent; interpret any discrepancy against HPA's sampled-cell evidence (general IHC practice; HPA tissue IHC). |
| Diffuse brown haze hides the granular pattern. | Nonspecific binding or detection-system background may obscure the reported cytoplasmic and membranous signal (general IHC practice; HPA tissue IHC). | Inspect no-primary and negative tissue controls, blocking and washing; optimize conditions against a documented positive cell type without assuming a CHPF-specific fixation effect (general IHC practice; HPA tissue IHC). |
| A suspected Golgi-associated signal seems weaker than broad cytosolic staining. | UniProt annotates Golgi membrane and cytosolic locations, while tissue HPA describes a granular cytoplasmic and membranous pattern (UniProt Q8IZ52 subcellular location; HPA tissue IHC). | Score the visible cellular pattern and documented cell type; do not require a sharply resolved Golgi outline in chromogenic tissue IHC (HPA tissue IHC; general IHC practice). |
| A slide looks different from HPA's image or its reported intensity. | HPA's Approved tissue pattern has medium consistency with RNA data, and its cell-level observations vary by tissue (HPA tissue IHC). | Record the exact cell type, compartment and control results; compare with the matching HPA tissue entry before calling the finding discordant (HPA tissue IHC; general IHC practice). |
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 and expect staining in glandular cells (HPA: Appendix glandular cells, Medium). Run adipose tissue as the negative comparator, focusing on adipocytes (HPA: adipocytes, Not detected); on the appendix slide, use unstained nonglandular cells as an internal background reference only if they are present, without assuming they are CHPF-negative.
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 no-primary (secondary-only) and host-species- and clonality-matched isotype controls, plus CHPF-knockout tissue if available or a peptide-competition control as illustrated for the catalog antibody (A30610 caption: peptide block). For chromogenic appendix IHC, quench endogenous peroxidase and check gland mucus and luminal material for nonspecific signal (standard IHC practice).
⚠️Feasibility: A CHPF-specific fixation window and the effect of fixation are unreported in the supplied evidence; the selected paraffin-section caption does not state a fixative (A30610 caption: fixative unreported). Retrieval dependency is also unreported, so optimize antigen retrieval empirically for paraffin sections (standard IHC practice). The supplied evidence does not establish that frozen sections or IF are easier than paraffin IHC; exclude appendix luminal debris from cellular scoring (standard IHC practice).
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 pattern, controls, and cell-specific scoring (UniProt Q8IZ52; HPA tissue IHC).
How should I retrieve CHPF in paraffin sections when staining is weak?
Start with citrate buffer at pH 6.0, heat-induced retrieval at 95–98 °C for 20 min (page retrieval rule: cytoplasmic/membrane antigen). Cool sections consistently, then compare the same tissue and antibody dilution across runs so retrieval is the main changed variable (standard IHC practice). CHPF has a membrane anchor at residues 16–34 and a lumenal region spanning 35–775, but the antibody’s epitope is unspecified, so topology alone cannot predict retrieval sensitivity (UniProt Q8IZ52 topology). If staining remains weak, test a more alkaline retrieval buffer on matched sections, checking whether signal improves without increased background or tissue damage (standard IHC practice).
Can I attribute weak CHPF staining to fixation conditions?
CHPF-specific fixation sensitivity is unknown because no target-specific fixation comparison is supplied (supplied evidence). The selected A30610 image documents staining in paraffin-embedded human cervix carcinoma, but its caption does not state the fixative (A30610 tissue-IHC caption). Record fixation method and duration for each specimen, then compare matched sections processed with the same retrieval, antibody incubation, and chromogen timing (standard IHC practice). If staining differs, first inspect morphology and internal cellular staining before assigning the difference to fixation; the HPA tissue pattern and CHPF topology do not establish a fixation effect (standard IHC practice; HPA tissue IHC; UniProt Q8IZ52 topology).
Which CHPF staining pattern should I expect in tissue sections?
Look for granular cytoplasmic and membranous staining, while judging its distribution within the relevant cell population rather than across the whole section (HPA tissue IHC). CHPF is annotated at the Golgi stack membrane, cytosol, mitochondrion, and mitochondrial matrix, so a single diffuse pattern is not definitive on its own (UniProt Q8IZ52 subcellular annotation). Its 16–34 membrane anchor and lumenal 35–775 region make perinuclear or punctate staining biologically plausible, but light microscopy cannot identify an organelle from morphology alone (UniProt Q8IZ52 topology; standard IHC practice). Compare the pattern with adjacent tissue, cellular morphology, and the peptide-blocked A30610 image when assessing specificity (A30610 tissue-IHC caption; standard IHC practice).
Can this IHC result distinguish CHPF isoforms or epitope accessibility?
CHPF has 3 annotated isoforms, but the supplied antibody information does not map its epitope to an isoform-specific sequence (UniProt Q8IZ52 isoforms; supplied antibody evidence). Accordingly, score staining as CHPF immunoreactivity rather than assigning it to one isoform (UniProt Q8IZ52 isoforms; standard IHC interpretation). The protein has a lumenal region spanning residues 35–775 and glycosylation sites at 138 and 361; these annotations identify potential epitope-context questions, not demonstrated masking in sections (UniProt Q8IZ52 topology and glycosylation). The A30610 peptide-blocked image supports a reagent-specificity check, but peptide competition alone cannot establish isoform selectivity or exclude every tissue artefact (A30610 tissue-IHC caption; standard IHC practice).
How can I check the CHPF pattern by multiplex IF?
Use a separate IF/ICC optimization and pair CHPF with an epithelial marker when examining the glandular cells reported as positive in cervix tissue (HPA tissue IHC; standard IF practice). Select spectrally separated fluorophores and place the weaker signal in a channel with less tissue autofluorescence, checking unstained and single-label controls before interpreting overlap (standard IF practice). Choose permeabilisation after determining whether the antibody recognizes CHPF’s cytoplasmic residues 1–15 or lumenal residues 35–775; the epitope side is not supplied (UniProt Q8IZ52 topology; supplied antibody evidence). Compare any puncta with CHPF’s annotated Golgi location and the reported cytosolic, vesicular, and centrosomal IF patterns, without treating colocalisation as proof of identity (UniProt Q8IZ52 subcellular annotation; HPA subcellular).
What should I check when CHPF chromogenic staining looks widespread?
Check a no-primary control for nonspecific detection and review the peroxidase block when using a peroxidase-based chromogenic workflow (standard IHC practice). Compare background in tissue edges, damaged regions, and empty spaces with intracellular signal in intact cells before changing antibody concentration (standard IHC practice). HPA reports granular cytoplasmic and membranous expression in several tissues, alongside undetected staining in specified cell populations; uniform colour across every structure deserves scrutiny (HPA tissue IHC). Keep retrieval at citrate pH 6.0, 95–98 °C for 20 min while varying one background-control step at a time, and compare with the peptide-blocked A30610 image (page retrieval rule; A30610 tissue-IHC caption; standard IHC practice).
How should I score CHPF staining across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because HPA reports CHPF staining by cell type and describes granular cytoplasmic and membranous expression (HPA tissue IHC). For comparable sections, record the percentage of positive cells and an intensity-based H-score using the same threshold and scoring rules throughout (standard IHC practice). Normalise positive-cell counts to the number of eligible cells, or report positive-cell density per mm² of viable tissue when cell counts are impractical (standard IHC practice). Exclude necrotic and poorly preserved areas consistently, and report cytoplasmic and membranous scores separately if their distributions differ (standard IHC practice; HPA tissue IHC).
When is a CHPF-positive IHC result convincing?
A convincing result has intracellular granular cytoplasmic or membranous staining in morphologically intact cells, with a plausible cell-type distribution (HPA tissue IHC; standard IHC practice). HPA reports medium staining in cervix glandular cells but no detection in oral mucosa squamous epithelial cells or adipocytes, so cell identity matters more than a whole-section average (HPA tissue IHC). Treat isolated nuclear colour, tissue-edge enhancement, necrotic deposits, or staining persisting in a no-primary control as possible artefacts requiring review (UniProt Q8IZ52 subcellular annotation; standard IHC practice). Interpret the A30610 peptide-blocked cervix carcinoma image as a useful specificity control, while recognizing that its caption does not identify the fixative (A30610 tissue-IHC caption).
Boster reagents
Best CHPF / Chondroitin polymerizing factor, non-catalytic subunit IHC Antibodies
A30610 is an anti-CHPF antibody with IHC data from paraffin-embedded human cervix carcinoma and IF data from MCF7 cells (catalog image captions); stated reactivity covers human, mouse and rat (catalog reactivity).
Real IHC data
Anti-CHSY2 CHPF Antibody
Cat # A30610
A30610 has an IHC image of paraffin-embedded human cervix carcinoma tissue with peptide blocking shown alongside it (catalog IHC image caption). A30610 also has an IF image of MCF7 cells with peptide blocking shown alongside it (catalog IF image caption); IHC, IF and ICC are listed applications (catalog applications).
Which to pick: For tissue IHC, choose A30610: its own image shows paraffin-embedded human cervix carcinoma tissue (catalog IHC image caption); the fixative is unreported (catalog IHC image caption). For IF/ICC, choose A30610 because both are listed applications (catalog applications), and its own IF image shows MCF7 cells (catalog IF image caption). For mouse or rat work, A30610 lists reactivity with both species (catalog reactivity); it is rabbit polyclonal (catalog host and dilution details), while the supplied IHC and IF images show human samples (catalog image captions).
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: Skeletal myocytes: undetected despite high muscle expression (HPA tissue IHC; UniProt); Isoform / epitope: 3 isoforms; check cytosolic vs lumenal epitope (UniProt); Regulation: Stimulus-specific regulation not 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.