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CMTM8 / CKLF-like MARVEL transmembrane domain-containing protein 8 · IHC design guide
Design Immunohistochemistry for CMTM8
Plan chromogenic IHC for CMTM8 in paraffin sections with the catalog antibody at 1:100–1:300 (datasheet). Compare liver hepatocytes or pancreatic exocrine cells with appendix glandular cells reported as undetected (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CMTM8 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 several tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic in hepatocytes and pancreatic exocrine cells (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Epididymis+4 more · see all | |
| Negative control | Appendix+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent (standard IHC practice; not target-specific) | |
| Caveat | Medium antibody–RNA consistency; verify staining (HPA tissue IHC) | |
| Regulation | Specific expression regulation not annotated (UniProt) | |
| Isoform / epitope | 2 isoforms; check extracellular versus cytoplasmic epitope (UniProt) |
Section 1
Recommended CMTM8 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet) appears alongside four published CMTM8 IHC methods (PMC9468640; PMC4722886; PMC9013447; PMC7859753).
| Sample | Paraffin-embedded Human Tonsils tissue; fixative not specified (datasheet A11789) |
| Fixation | Image fixative and duration unreported (datasheet A11789); 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 Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear 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-CMTM8, 1:100-1:300 (datasheet A11789) |
| 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 | CMTM8-positive staining in glandular cells of epididymis (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in several tissues, including liver and pancreas. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 HIER at 95–98 °C for 20 min (page retrieval); use an article’s retrieval conditions when reproducing its method.
Section 2
What Is the Expected CMTM8 Staining Pattern?
In paraffin-section IHC, expect predominantly cytoplasmic CMTM8 staining in hepatocytes and pancreatic exocrine glandular cells, with medium staining reported in both (HPA: tissue IHC). This observed pattern can coexist with a four-pass membrane protein annotated in the membrane, cytoplasm and nucleus (UniProt Q8IZV2 topology and subcellular location). HPA rates its tissue IHC evidence Approved, with medium consistency against RNA data and external verification pending (HPA: tissue IHC reliability).
| Cytoplasmic staining in hepatocytes and pancreatic exocrine glandular cells. | This matches the reported IHC profile; HPA scores both cell populations Medium, so compare localisation and cell identity as well as intensity (HPA: tissue IHC). |
| Nuclear staining dominates the paraffin-section result, with little cytoplasmic staining. | Treat this as an IHC pattern requiring validation before calling it positive: HPA reports cytoplasmic tissue IHC, although UniProt includes nucleus and HPA ICC-IF reports nucleoplasm (HPA: tissue IHC and subcellular; UniProt Q8IZV2 subcellular location). |
| Strong staining appears mainly in cells HPA lists as not detected, such as appendix glandular cells. | This conflicts with that reference cell-type result and raises concern for cross-reactivity or detection background; a single discordant section does not establish either cause (HPA: tissue IHC; general IHC practice). |
| Chromogen is spread across tissue structures without a clear cellular pattern. | A diffuse deposit is difficult to score as CMTM8; assess background and endogenous detection activity with appropriate controls before interpreting localisation (general chromogenic IHC practice). |
| No staining is visible in hepatocytes or pancreatic exocrine glandular cells. | Recheck the assay before interpreting the specimen as negative: HPA reports Medium staining in these cells, but its tissue IHC evidence has only medium consistency with RNA data (HPA: tissue IHC and reliability). |
💡Expected CMTM8 appearanceCall an IHC result consistent with the reference when medium cytoplasmic staining identifies hepatocytes or pancreatic exocrine glandular cells; strong staining confined to an HPA not-detected cell population is suspect (HPA: tissue IHC).
| Which compartment should guide IHC scoring? | Use the observed cytoplasmic tissue pattern as the reference (HPA: tissue IHC). Four transmembrane segments and membrane, cytoplasm and nucleus annotations broaden plausible biology but do not predict a membrane-only chromogenic pattern (UniProt Q8IZV2 topology and subcellular location). |
| Which tissue and cell type make a useful reference? | HPA reports Medium staining in liver hepatocytes, pancreatic exocrine glandular cells and lung macrophages; it reports appendix glandular cells as Not detected (HPA: tissue IHC). Score the specified cell population rather than whole-section colour (general IHC practice). |
| How secure is the tissue IHC pattern? | The tissue profile is Approved but has medium consistency with RNA expression and awaits external verification (HPA: tissue IHC reliability). HPA055077 is IHC Approved; the supplied record does not establish an IHC Enhanced result (HPA: antibody validation). |
| Does an isoform or processing event explain a different pattern? | UniProt lists two isoforms, no signal peptide or propeptide, and a chain spanning residues 1–173 (UniProt Q8IZV2). These annotations alone cannot assign an antibody epitope or explain a discordant staining compartment. |
| Q: What should an IF/ICC result show? | A: HPA reports approved nucleoplasmic localisation in ICC-IF images from HEK293 and Hep-G2, with HPA073258 ICC Supported (HPA: subcellular and antibody validation). Interpret that result within ICC-IF; it does not replace the cytoplasmic tissue IHC reference (HPA: tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| The expected liver or pancreas cells are unstained. | The section conflicts with HPA's Medium hepatocyte or pancreatic exocrine glandular-cell staining; the reason cannot be assigned from that comparison alone (HPA: tissue IHC). | Check the IHC-validated antibody's protocol, retrieval, dilution and detection steps against the actual run, then repeat alongside a reference section (general IHC practice). |
| Only nuclei stain in an IHC section. | This differs from HPA's cytoplasmic tissue IHC profile, although nuclear localisation is annotated by UniProt and nucleoplasmic ICC-IF is reported by HPA (HPA: tissue IHC and subcellular; UniProt Q8IZV2). | Review morphology and controls, then seek independent IHC confirmation before treating nuclear-only staining as the expected tissue pattern (general IHC practice). |
| Appendix glandular cells stain as strongly as the intended positive cells. | HPA lists appendix glandular cells as Not detected; cross-reactivity or detection background is possible but unproven (HPA: tissue IHC; general IHC practice). | Compare a no-primary control and cell-level localisation across sections; investigate persistent discordance with an independent validation approach (general IHC practice). |
| Diffuse chromogen obscures cell borders. | Nonspecific reagent binding or, with enzyme-based detection, endogenous activity can contribute to background (general chromogenic IHC practice). | Inspect a no-primary control and the assay's blocking, washing and endogenous-activity controls; adjust only steps relevant to the detection system used (general IHC practice). |
| Pancreas looks positive overall, but the stained cells are unclear. | A tissue-wide impression cannot establish the specified HPA result, which is Medium staining in exocrine glandular cells (HPA: tissue IHC). | Use morphology and counterstain to identify exocrine glandular cells, then record their compartment and intensity separately from neighbouring cells (general IHC practice). |
| ICC-IF shows nucleoplasmic signal while IHC shows cytoplasmic signal. | Those are the distinct reported assay observations, with separate HPA antibody validation entries (HPA: subcellular, tissue IHC and antibody validation). | Report each result with its assay and antibody context; assess any unexplained discrepancy within that assay's controls before combining interpretations (general IHC/ICC-IF practice). |
Experiment evidence
IHC & IF images showing CMTM8 staining
A11789 · IHCImmunohistochemistry (IHC) analysis of paraffin-embedded Human Tonsils, antibody was diluted at 1:200.
A11789 · IHCImmunohistochemistry (IHC) analysis of paraffin-embedded Human Tonsils, antibody was diluted at 1:200.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000170293-CMTM8/tissue/cerebral+cortex#imid_15336270
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000170293-CMTM8/tissue/colon#imid_15335648
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000170293-CMTM8/tissue/liver#imid_15335641
HPA · PancreasHuman Protein Atlas IHC, Pancreas. Source: https://www.proteinatlas.org/ENSG00000170293-CMTM8/tissue/pancreas#imid_15335608
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA073258; green = CMTM8, blue = nucleus, red = microtubules.
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA073258; green = CMTM8, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CMTM8 IHC & IF
🧪Run liver first: hepatocytes should show staining (HPA: Medium in liver hepatocytes). Use appendix glandular cells as the negative tissue (HPA: Not detected in appendix glandular cells); on the liver slide, assess surrounding cells without clear staining as an internal background reference, without assuming they lack CMTM8.
Positive control tissue: Epididymis (Glandular cells, HPA Medium)
Negative control tissue: Appendix (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CMTM8 in HEK293, Hep-G2, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) control, a control immunoglobulin matched to the primary antibody’s host species and class and appropriate to its clonality, and a CMTM8 knockout or immunizing-peptide block if available. In liver, check endogenous peroxidase and, if using biotin-based detection, endogenous biotin as potential sources of chromogenic background (HPA: liver hepatocytes selected as the positive tissue).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported; the A11789 paraffin-section caption reports 1:200 in human tonsil but leaves the fixative unreported (A11789 tissue-IHC caption). Retrieval dependence is unreported, and the supplied evidence does not establish whether frozen sections or IF would be easier; HPA does show ICC-IF images in HEK293 and Hep-G2 with approved nucleoplasmic localization (HPA subcellular). In liver, assess pigment and endogenous enzyme background when interpreting hepatocyte staining (HPA: Medium in liver hepatocytes).
HPA tissue IHC evidence for CMTM8
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data. 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 |
|---|---|---|---|---|
| Epididymis | Glandular cells | Medium | Protein (IHC) | HPA → |
| Liver | Hepatocytes | Medium | Protein (IHC) | HPA → |
| Lung | Macrophages | Medium | Protein (IHC) | HPA → |
| Pancreas | Exocrine glandular cells | Medium | Protein (IHC) | HPA → |
| Placenta | Decidual cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Endometrium | Cells in endometrial stroma | Not detected | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CMTM8 IHC Tips
Troubleshoot CMTM8 staining in paraffin sections by checking retrieval, cellular compartment, tissue context and controls before assigning a score.
How should I retrieve CMTM8 in paraffin sections when staining is weak?
Use Tris-EDTA at pH 9.0 for heat-induced retrieval at 95–98 °C for 20 min (page retrieval setting). After cooling, compare retrieved and unretrieved sections stained in the same run, using the catalog antibody's 1:200 tonsil image as a dilution reference rather than proof that your tissue will stain (A11789 IHC caption; standard IHC practice). If signal remains weak, test a shorter or longer heating interval on adjacent sections while holding detection conditions constant (standard IHC practice). Record tissue preservation alongside signal, since damaged morphology makes compartment-level interpretation unreliable (standard IHC practice).
Could fixation explain variable CMTM8 staining across my paraffin sections?
CMTM8-specific fixation sensitivity is unknown from the supplied evidence; the catalog image identifies paraffin-embedded tonsil and 1:200 antibody dilution, but reports no fixative (A11789 IHC caption). Compare sections with documented fixation histories and keep section thickness, retrieval, antibody incubation and chromogen development consistent within the comparison (standard IHC practice). Examine morphology and staining together: poor preservation or uneven penetration can confound a weak result before target abundance is considered (standard IHC practice). Treat a fixation-related change as an experimental observation only after matched tissue regions and staining controls show the same pattern reproducibly (standard IHC practice).
Which cellular compartments should count as plausible CMTM8 signal?
Assess membrane, cytoplasmic and nuclear staining separately because all three locations appear in the CMTM8 record (UniProt Q8IZV2 localisation). The protein has 4 predicted transmembrane segments at residues 40–60, 70–90, 105–125 and 147–167, so a membrane-associated pattern is biologically plausible (UniProt Q8IZV2 topology). Tissue IHC reports cytoplasmic expression in several tissues, including liver and pancreas, whereas the subcellular IF record approves nucleoplasmic localisation (HPA tissue IHC; HPA subcellular). Keep those compartments distinct in the scoring sheet and inspect whether apparent nuclear colour is confined to intact cells rather than overlying pigment or diffuse chromogen (standard IHC practice).
How do isoforms and membrane topology affect CMTM8 antibody interpretation?
Check the catalog antibody's immunogen sequence against both annotated CMTM8 isoforms before assigning a negative stain to absent protein (UniProt Q8IZV2 isoforms; standard IHC practice). CMTM8 has 2 isoforms and a MARVEL domain spanning residues 36–168, with 4 transmembrane segments within the protein (UniProt Q8IZV2). An epitope inside or near a membrane-spanning region may be harder to expose in a section; test retrieval on matched sections without presuming which isoform the antibody detects (UniProt Q8IZV2 topology; standard IHC practice). The supplied record lists 0 glycosylation sites and 0 modified residues, so do not invoke either modification to explain staining differences without new evidence (UniProt Q8IZV2).
How can I use IF to check an ambiguous CMTM8 IHC pattern?
Use IF as a separate spatial check, pairing CMTM8 with a validated marker for the cell population being assessed, such as a macrophage marker when examining lung macrophages (HPA tissue IHC: medium staining in lung macrophages; standard IF practice). Choose well-separated fluorophores after checking tissue autofluorescence, and include single-stain controls to assess bleed-through (standard IF practice). If the antibody epitope is intracellular, optimise mild permeabilisation; if it faces the extracellular side of an intact membrane, compare conditions without permeabilisation (UniProt Q8IZV2 topology; standard IF practice). HPA reports nucleoplasmic IF localisation and images from HEK293 and Hep-G2, but that does not establish the catalog antibody's IF performance or fixation conditions (HPA subcellular; A11789 IHC caption).
What controls help identify nonspecific CMTM8 chromogenic staining?
Run a no-primary control and inspect matched positive and low-expression tissue regions before changing the antibody concentration (standard IHC practice). For context, HPA reports medium hepatocyte staining in liver and no detected glandular-cell staining in appendix; these are comparison patterns, not guaranteed controls for every assay (HPA tissue IHC). Check that the routine peroxidase block suppresses endogenous enzyme activity, then compare DAB development times across sections stained together (standard chromogenic IHC practice). Diffuse colour across unrelated cell types, section edges or damaged areas warrants inspection of blocking, washing and chromogen exposure before interpreting CMTM8 abundance (standard IHC practice).
How should I quantify CMTM8 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, then record the percentage of positive cells and an intensity-based H-score for chromogenic CMTM8 staining (standard IHC practice). Score membrane, cytoplasm and nucleus separately, since the record lists all three locations and HPA tissue IHC emphasises cytoplasmic staining (UniProt Q8IZV2 localisation; HPA tissue IHC). Normalise positive-cell counts to the number of evaluable cells in the same compartment and region, or report positive-cell density per mm² of viable tissue (standard IHC practice). Keep thresholds, imaging settings and exclusion rules constant across samples, and report excluded necrotic or poorly preserved regions (standard IHC practice).
When is a CMTM8-positive IHC pattern credible rather than artefactual?
Look for staining in intact cells with a compartment and tissue distribution supported by the evidence, such as cytoplasmic hepatocyte or pancreatic exocrine-cell signal (HPA tissue IHC). A nuclear signal merits separate review because nucleoplasmic localisation is approved in IF, while tissue IHC describes a mainly cytoplasmic profile (HPA subcellular; HPA tissue IHC). Check suspicious staining against a no-primary control and neighbouring viable tissue; edge concentration, necrotic deposits and residual endogenous peroxidase can mimic chromogenic positivity (standard IHC practice). Treat staining in an unexpected cell population as provisional until morphology, control sections and a reproducible cellular pattern support it (standard IHC practice).
Boster reagents
Best CMTM8 / CKLF-like MARVEL transmembrane domain-containing protein 8 IHC Antibodies
A11789 has real IHC data from paraffin-embedded human tonsils (catalog image caption); IF is listed as an application without an IF image (catalog applications; catalog IF image alts). Human and mouse reactivity are listed (catalog reactivity).
Real IHC data
Anti-CMTM8/Cklfsf8 Antibody
Cat # A11789
A11789 will render with an IHC figure of paraffin-embedded human tonsils at 1:200 (catalog image caption). The rabbit polyclonal antibody lists IHC and IF applications and human and mouse reactivity; no IF figure is supplied (catalog host and dilution_raw; catalog applications and reactivity; catalog IF image alts).
Which to pick: For tissue IHC, choose A11789: its own image documents paraffin-embedded human tonsils at 1:200, while the fixative is unreported (catalog image caption). For IF/ICC, A11789 lists IF and an IF dilution of 1:50, but supplies no IF image or ICC validation (catalog applications; catalog IF dilution; catalog IF image alts). For human or mouse samples, A11789 is the listed rabbit polyclonal option with both species in its reactivity list; the pictured IHC sample is human (catalog host and dilution_raw; catalog reactivity; catalog image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q8IZV2 (CKLF8_HUMAN, CKLF-like MARVEL transmembrane domain-containing protein 8).
- Human Protein Atlas. CMTM8 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. CMTM8 subcellular location (ICC-IF): Localized to the nucleoplasm..
- Human Protein Atlas. CMTM8 antibody validation summary (2 antibodies).
- Identification of prognostic biomarkers in the CMTM family genes of human ovarian cancer through bioinformatics analysis and experimental verification. Frontiers in genetics 2022 — PMC9468640.
- CMTM8 inhibits the carcinogenesis and progression of bladder cancer. Oncology reports 2015 — PMC4722886.
- Identification and validation of EMT-immune-related prognostic biomarkers CDKN2A, CMTM8 and ILK in colon cancer. BMC gastroenterology 2022 — PMC9013447.
- CMTM8 as an LPA1-associated partner mediates lysophosphatidic acid-induced pancreatic cancer metastasis. Annals of translational medicine 2021 — PMC7859753.
- PubMed PMID:12782130 — UniProt-cited evidence.
- PubMed PMID:17681841 — UniProt-cited evidence.
- PubMed PMID:16641997 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CMTM8 (CKLF-like MARVEL transmembrane domain-containing protein 8). Expected localisation Cytoplasmic staining in several tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: A11789 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Epididymis (Glandular cells); negative Appendix. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded Human Tonsils tissue; fixative not specified (datasheet A11789); 2. Fixation: Image fixative and duration unreported (datasheet A11789); 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 Tris-EDTA buffer, pH 9.0 , 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-CMTM8, 1:100-1:300 (datasheet A11789); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep paraffin-section fixation consistent (standard IHC practice; not target-specific); Caveat: Medium antibody–RNA consistency; verify staining (HPA tissue IHC); Isoform / epitope: 2 isoforms; check extracellular versus cytoplasmic epitope (UniProt); Regulation: Specific expression regulation not annotated (UniProt). Evidence: UniProt Q8IZV2, HPA tissue IHC · Approved, HPA ICC-IF · nucleoplasm., Datasheet A11789, PMC9468640, PMC4722886. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CMTM8/immunohistochemistry-ihc-guide.