This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
C1QTNF1 / Complement C1q tumor necrosis factor-related protein 1 · IHC design guide
Design Immunohistochemistry for C1QTNF1
Plan chromogenic IHC-P for C1QTNF1 with the IHC-validated antibody starting at 10 μg/mL (datasheet: A09550-1). Compare cytoplasmic staining in kidney tubules and colon glands, while accounting for uncertain tissue localisation of this secreted protein (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
C1QTNF1 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 most tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in kidney tubules and colon glands (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Colon+4 more · see all | |
| Negative control | Caudate+1 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A09550-1) | |
| Caveat | Secreted variants may separate RNA and protein locations (HPA tissue IHC) | |
| Regulation | Regulation unreported (UniProt) | |
| Isoform / epitope | 2 isoforms; mature chain spans residues 26–281; epitope unmapped (UniProt) |
Section 1
Recommended C1QTNF1 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (page contract) with a published C1QTNF1 tissue IHC method (PMC10387556).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A09550-1); 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-C1QTNF1, 10 μg/mL (datasheet A09550-1) |
| 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 | C1QTNF1-positive staining in glandular cells of colon (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page retrieval setting); the published IHC excerpt does not specify retrieval (PMC10387556).
Section 2
What Is the Expected C1QTNF1 Staining Pattern?
C1QTNF1 is a secreted protein with a cleaved signal peptide and no transmembrane segment (UniProt Q9BXJ1 topology). In paraffin-section IHC, HPA reports cytoplasmic staining in most tissues, including high staining in several epithelial and other cell populations (HPA tissue IHC). Treat this as a provisional pattern: HPA rates the tissue IHC evidence Uncertain because secretion can separate protein staining from the cells expressing its RNA (HPA tissue IHC reliability).
| Clear cytoplasmic staining in colon or duodenal glandular cells, or kidney tubular cells (HPA tissue IHC: High). | This matches reported high-staining cell populations (HPA tissue IHC). Compare the named cells with nearby structures and a negative reagent control before calling the section positive (standard IHC practice). |
| Predominantly nuclear or sharply membrane-restricted chromogenic staining, with little cytoplasmic signal. | This departs from the reported tissue IHC profile (HPA tissue IHC: cytoplasmic). Check morphology, detection background and antibody specificity (standard IHC practice). Nuclear staining in ICC-IF is a separate HPA observation and does not validate nuclear IHC staining (HPA subcellular ICC-IF). |
| Strong staining mainly in cells outside the reported positive population of the selected tissue. | Treat the cell assignment as unresolved; cross-reactivity or endogenous detection activity are possible explanations (standard IHC practice). HPA's uncertain tissue reliability and C1QTNF1 secretion prevent a firm cell-of-origin claim from staining alone (HPA tissue IHC; UniProt Q9BXJ1 subcellular location). |
| Diffuse color across cells, stroma and blank areas, without a recognizable cell pattern. | This is background until controls establish otherwise (standard IHC practice). It cannot be scored against HPA's reported cytoplasmic cell pattern (HPA tissue IHC); inspect reagent controls and detection conditions (standard IHC practice). |
| No detectable staining in colon glandular cells or kidney tubular cells (HPA tissue IHC: High). | Investigate assay performance using a control section and the antibody's IHC-P instructions (standard IHC practice). A negative run does not overturn HPA's reported staining, and its Uncertain reliability means that report is not an absolute positive-control guarantee (HPA tissue IHC). |
💡Expected C1QTNF1 appearanceA persuasive positive is discernible cytoplasmic staining in a reported high-staining cell population, such as colon glandular cells or kidney tubular cells (HPA tissue IHC: High); diffuse color without cell definition is background (standard IHC practice), and the reference pattern remains Uncertain (HPA tissue IHC reliability).
| Secretion and topology (UniProt Q9BXJ1). | C1QTNF1 has a signal peptide, is secreted and has no transmembrane segment (UniProt Q9BXJ1). Staining need not identify the cell that made the protein; tissue RNA and protein locations may differ (HPA tissue IHC reliability). |
| Processing and epitope position (UniProt Q9BXJ1). | The annotated signal peptide spans residues 1–25 and the mature chain spans 26–281 (UniProt Q9BXJ1). Interpret an antibody result in light of its stated immunogen or epitope, if available (standard IHC practice); no epitope is supplied here. |
| Variants and molecular features (UniProt Q9BXJ1). | UniProt lists 2 isoforms, one glycosylation site at residue 93, a collagen-like region and a C1q domain (UniProt Q9BXJ1). These annotations alone do not establish which isoform or feature an IHC antibody detects. |
| Antibody and tissue-evidence limits (HPA antibodies; HPA tissue IHC). | The listed IHC antibody CAB025429 is rated Uncertain, while HPA051101 is Approved for ICC only (HPA antibodies). HPA also rates the tissue IHC pattern Uncertain (HPA tissue IHC); do not treat ICC approval as IHC validation. |
| IF/ICC Q&A: should nuclear signal be expected? | HPA reports approved nucleoplasm and cytosol locations in ICC-IF images from A-549, PC-3 and U2OS (HPA subcellular ICC-IF). That observation answers the IF/ICC question; it does not change the cytoplasmic tissue IHC reference pattern (HPA tissue IHC). |
| Choice of tissue control (HPA tissue IHC). | HPA reports high staining in colon glandular cells and kidney tubular cells, but no detected staining in caudate or hippocampal glial cells (HPA tissue IHC). Use these as comparison patterns with HPA's Uncertain reliability in mind (HPA tissue IHC reliability). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in a reported high-staining cell population (HPA tissue IHC: High). | The IHC run may have failed, or this specimen may differ from the reported HPA pattern (standard IHC practice; HPA tissue IHC reliability: Uncertain). | Check a control section, reagent omission control and the catalog antibody's IHC-P instructions; assess retrieval and detection conditions as general IHC variables (standard IHC practice). |
| Color appears throughout the section, including spaces without cells. | Nonspecific reagent binding or detection background may obscure the reported cytoplasmic pattern (standard IHC practice; HPA tissue IHC). | Compare with a primary-antibody omission control, then review blocking, washing and chromogen development (standard IHC practice). |
| Brown deposit persists when the primary antibody is omitted. | Endogenous enzyme activity or another detection-system source is possible in chromogenic IHC (standard IHC practice). | Review the detection-system controls and apply the appropriate endogenous-activity block for that system (standard IHC practice). |
| A bright nuclear pattern dominates the paraffin-section result. | It conflicts with HPA's cytoplasmic tissue IHC profile, although HPA reports nucleoplasm staining in ICC-IF (HPA tissue IHC; HPA subcellular ICC-IF). | Score the IHC result separately from ICC-IF; verify cell boundaries, controls and staining with an independently validated IHC reagent if available (standard IHC practice). |
| Strong staining occurs in an unexpected cell population. | Cross-reactivity or detection background is possible; secreted C1QTNF1 also complicates assigning protein to its producing cell (standard IHC practice; UniProt Q9BXJ1 subcellular location). | Inspect the cell type and controls, then seek independent specificity evidence before assigning cellular expression (standard IHC practice; HPA tissue IHC reliability: Uncertain). |
| Glial cells stain strongly where HPA reports no detection (HPA tissue IHC: caudate and hippocampus). | The result differs from those HPA observations; nonspecific staining or specimen variation remains possible (HPA tissue IHC; standard IHC practice). | Check morphology and omission controls, then compare with a reported high-staining tissue in the same run; avoid treating HPA's Uncertain pattern as a definitive exclusion rule (standard IHC practice; HPA tissue IHC reliability). |
Experiment evidence
IHC & IF images showing C1QTNF1 staining
A09550-1 · IHCImmunohistochemistry of CTRP1 in human kidney tissue with CTRP1 antibody at 10 μg/mL.
A09550-1 · IFImmunofluorescence of CTRP1 in Human Kidney cells with CTRP1 antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000173918-C1QTNF1/tissue/cerebral+cortex#imid_6961312
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000173918-C1QTNF1/tissue/colon#imid_6961230
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000173918-C1QTNF1/tissue/liver#imid_6961231
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000173918-C1QTNF1/tissue/kidney#imid_6961232
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA051101; green = C1QTNF1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA051101; green = C1QTNF1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for C1QTNF1 IHC & IF
🧪Run kidney first: tubular cells should stain (HPA: High in kidney cells in tubules). Use caudate glial cells as the negative tissue (HPA: Not detected in caudate glial cells); on the kidney slide, treat neighboring cells without specific staining as internal background comparators, without assuming every non-tubular cell is negative (standard IHC practice).
Positive control tissue: Colon (Glandular cells, HPA High)
Negative control tissue: Caudate (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show C1QTNF1 in A-549, PC-3, U2OS, with annotated localisation: Nucleoplasm (approved), Cytosol (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species and clonality; confirm specificity with a knockout specimen or validated peptide block where available (standard IHC practice). For chromogenic kidney IHC, block endogenous peroxidase and inspect control sections for residual background (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and retrieval dependency are unreported in the supplied evidence; the selected A09550-1 kidney IHC caption also leaves the fixative unreported (selected SKU caption). The evidence does not establish whether frozen sections or IF/ICC are easier; HPA reports nucleoplasm and cytosol in its ICC-IF images (HPA: subcellular summary). In kidney, assess endogenous peroxidase background before interpreting tubular signal (standard IHC practice; HPA: High in kidney cells in tubules).
HPA tissue IHC evidence for C1QTNF1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex. Pending external verification.). 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 |
|---|---|---|---|---|
| Colon | Glandular cells | High | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | High | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | High | Protein (IHC) | HPA → |
| Kidney | Cells in tubules | High | Protein (IHC) | HPA → |
| Lymph node | Germinal center cells | High | Protein (IHC) | HPA → |
Section 3
Advanced C1QTNF1 IHC Tips
Use the kidney IHC example as a reference point while checking retrieval, tissue morphology, cell identity, and the limits of the available validation (selected A09550-1 tissue-IHC caption).
What retrieval should I start with when C1QTNF1 staining is weak in paraffin sections?
Start with citrate buffer at pH 6.0 for HIER at 95–98 °C for 20 min (page retrieval setting). Keep section thickness, cooling, and antibody concentration constant while assessing retrieval, because the kidney image reports 10 μg/mL antibody but no retrieval method (selected A09550-1 tissue-IHC caption; standard IHC practice). If staining remains weak, test another retrieval condition as a documented fallback on adjacent sections with the same detection system (standard IHC practice). Judge any gain in signal against preserved morphology, staining in kidney tubules, and a no-primary control; damaged tissue or widespread chromogen can make retrieval appear successful (HPA tissue IHC: kidney tubules High; standard IHC practice).
How should I investigate fixation-related differences between C1QTNF1 IHC runs?
Target-specific fixation sensitivity is unknown: the kidney tissue-IHC caption specifies 10 μg/mL antibody but does not identify a fixative (selected A09550-1 tissue-IHC caption). For paraffin sections, record fixative, fixation duration, processing, and section age before comparing runs, since these variables can change apparent antigen accessibility (standard IHC practice). Keep citrate pH 6.0 retrieval at 95–98 °C for 20 min constant while assessing those variables (page retrieval setting). If staining varies, compare matched sections with preserved morphology and identical detection chemistry; the supplied evidence does not establish a C1QTNF1-specific fixation effect (standard IHC practice; selected A09550-1 tissue-IHC caption).
Should I expect intracellular or extracellular C1QTNF1 staining in kidney IHC?
Score staining by compartment as well as cell type: C1QTNF1 is annotated as secreted and lacks a transmembrane segment, while tissue IHC describes mostly cytoplasmic expression (UniProt Q9BXJ1; HPA tissue IHC). Kidney tubule cells are reported as High, and the catalog antibody's kidney image used 10 μg/mL antibody (HPA tissue IHC: kidney tubules High; selected A09550-1 tissue-IHC caption). Extracellular chromogen may reflect deposited secreted protein, but that interpretation needs anatomical context and independent validation (UniProt Q9BXJ1: Secreted; standard IHC practice). Record nuclear staining separately: nucleoplasm is an approved IF location, yet IF localisation alone cannot establish the specificity of nuclear DAB in a tissue section (HPA subcellular; standard IHC practice).
Could the antibody epitope explain inconsistent staining across C1QTNF1 sections?
First obtain the catalog antibody's immunogen or epitope map; none is supplied here, so its coverage of the 2 annotated isoforms cannot be established from these data (UniProt Q9BXJ1: isoforms 1 and 2; supplied catalog evidence). The precursor has a signal sequence at residues 1–25, a collagen-like region at 99–140, and a C1q domain at 141–281 (UniProt Q9BXJ1). A glycosylation site is annotated at residue 93, but its effect on this antibody's tissue staining has not been tested here (UniProt Q9BXJ1; supplied catalog evidence). Compare staining after the fixed citrate pH 6.0 retrieval and document the epitope before attributing regional differences to processing or isoforms (page retrieval setting; standard IHC practice).
How can companion IF help assess the cells producing C1QTNF1 IHC signal?
On the companion IF/ICC page, multiplex C1QTNF1 with a marker for the expected cell population, such as kidney tubule cells when assessing the kidney IHC pattern (HPA tissue IHC: kidney tubules High; standard IF practice). Choose a spectrally separated, preferably far-red fluorophore and inspect unstained tissue in each channel to distinguish signal from tissue autofluorescence (standard IF practice). Decide permeabilisation by the epitope being tested: use it for an intracellular target and omit it when testing an accessible extracellular epitope (standard IF practice). C1QTNF1 is secreted without a transmembrane segment, while IF reports approved cytosol and nucleoplasm locations; the antibody's epitope side is unspecified here (UniProt Q9BXJ1; HPA subcellular; supplied catalog evidence).
What should I check when C1QTNF1 DAB staining appears diffuse?
Inspect a no-primary section and the tissue edges before changing antibody concentration; folds, drying, and edge staining can produce diffuse brown signal in chromogenic IHC (standard IHC practice). Include a peroxidase block before DAB detection and check whether residual endogenous activity persists in the control (standard IHC practice). The kidney image used 10 μg/mL antibody, which is a reference point for that image rather than a proven optimum for every section (selected A09550-1 tissue-IHC caption). If background rises with the primary antibody, titrate it on adjacent sections while holding citrate pH 6.0, 95–98 °C, 20 min retrieval and detection constant (page retrieval setting; standard IHC practice).
How should I quantify C1QTNF1 staining without conflating cell abundance and intensity? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell compartment and tissue region before scoring; kidney tubule cells are a documented High population for this target (HPA tissue IHC: kidney tubules High; standard IHC practice). For cellular DAB, record the percentage of viable target cells at intensity 0–3 and calculate an H-score on a 0–300 scale, or report percentage positive at a prespecified threshold (standard IHC practice). Normalise to the number of eligible cells, and record extracellular staining separately as positive area per mm² of evaluable tissue (standard IHC practice; UniProt Q9BXJ1: Secreted). Apply one threshold and the same exclusion rules for folds, edges, and necrosis across sections (standard IHC practice).
When is an apparent C1QTNF1-positive region convincing rather than artefactual?
A convincing kidney result should localise to intact tubule cells and remain distinguishable from the no-primary section; kidney tubule cells are High in tissue IHC (HPA tissue IHC: kidney tubules High; standard IHC practice). Treat staining confined to edges, folds, or necrotic areas cautiously, and use the no-primary control to assess endogenous enzyme signal after DAB development (standard IHC practice). Do not dismiss extracellular signal solely because it lies outside cells: C1QTNF1 is secreted and has no transmembrane segment (UniProt Q9BXJ1). Conversely, nuclear DAB or unexpected cell staining needs independent corroboration, especially because the tissue-IHC reliability assessment is Uncertain despite approved nucleoplasm localisation in IF (HPA tissue IHC: Uncertain; HPA subcellular; standard IHC practice).
Boster reagents
Best C1QTNF1 / Complement C1q tumor necrosis factor-related protein 1 IHC Antibodies
A09550-1 has human kidney tissue IHC and human kidney cell IF images (catalog image captions), with listed Human, Mouse and Rat reactivity (catalog reactivity).
Real IHC data
Anti-CTRP1 C1QTNF1 Antibody
Cat # A09550-1
A09550-1 is listed for IHC-P and IF (catalog applications). Its images show IHC in human kidney tissue at 10 μg/mL and IF in human kidney cells at 20 μg/mL (A09550-1 image captions).
Which to pick: For paraffin-section IHC, choose A09550-1: IHC-P is listed, and its own IHC caption shows human kidney tissue at 10 μg/mL; the fixative is unreported (catalog applications; A09550-1 IHC caption). For cell IF, choose A09550-1 based on its IF listing and human kidney cell image; ICC-specific validation is unreported (catalog applications; A09550-1 IF caption). For mouse or rat samples, A09550-1 has listed reactivity, though its displayed examples are human only and no clone is specified (catalog reactivity; image captions; catalog clone field).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9BXJ1 (C1QT1_HUMAN, Complement C1q tumor necrosis factor-related protein 1).
- Human Protein Atlas. C1QTNF1 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. C1QTNF1 subcellular location (ICC-IF): Localized to the nucleoplasm and cytosol..
- Human Protein Atlas. C1QTNF1 antibody validation summary (2 antibodies).
- Dynamic network biomarker C1QTNF1 regulates tumor formation at the tipping point of hepatocellular carcinoma. Biomolecules & biomedicine 2024 — PMC11293248.
- High C1QTNF1 expression mediated by potential ncRNAs is associated with poor prognosis and tumor immunity in kidney renal clear cell carcinoma. Frontiers in molecular biosciences 2023 — PMC10387556.
- PubMed PMID:12975309 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:16625196 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for C1QTNF1 (Complement C1q tumor necrosis factor-related protein 1). Expected localisation Cytoplasmic staining in most tissues (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A09550-1 at 10 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Colon (Glandular cells); negative Caudate. 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 A09550-1); 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-C1QTNF1, 10 μg/mL (datasheet A09550-1); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A09550-1); Caveat: Secreted variants may separate RNA and protein locations (HPA tissue IHC); Isoform / epitope: 2 isoforms; mature chain spans residues 26–281 ; epitope unmapped (UniProt); Regulation: Regulation unreported (UniProt). Evidence: UniProt Q9BXJ1, HPA tissue IHC · Uncertain, HPA ICC-IF · nucleoplasm and cytosol., Datasheet A09550-1, PMC10387556. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/C1QTNF1/immunohistochemistry-ihc-guide.