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CPNE8 / Copine-8 · IHC design guide
Design Immunohistochemistry for CPNE8
CPNE8 shows cytoplasmic and membranous staining in several tissues (HPA tissue IHC). This IHC-P guide covers fixation, antigen retrieval, controls, and chromogenic scoring with the IHC-validated antibody (datasheet: IHC 1:100–1:300).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CPNE8 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 and membranous staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic/membranous staining; high in hepatocytes (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Caudate+2 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Staining shows medium consistency with RNA data (HPA tissue IHC) | |
| Regulation | Expression regulation is unreported (UniProt) | |
| Isoform / epitope | 2 isoforms; epitope coverage is unknown (UniProt) |
Section 1
Recommended CPNE8 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is paired with one published CPNE8 xenograft tumor IHC protocol (PMC9379401).
| Sample | Paraffin-embedded human lung carcinoma tissue; fixative not specified (datasheet A15136-2) |
| Fixation | Image fixative and duration unreported (datasheet A15136-2); 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-CPNE8, 1:100-1:300 (datasheet A15136-2) |
| 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 | CPNE8-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: 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 antigen-retrieval setting); the article does not specify its antigen-repair conditions (PMC9379401).
Section 2
What Is the Expected CPNE8 Staining Pattern?
CPNE8 staining in paraffin sections is expected in the cytoplasm and along cell membranes, including kidney tubule cells, hepatocytes, cardiomyocytes, adipocytes and several glandular cell populations (HPA tissue IHC: high in these cells; cytoplasmic and membranous profile). UniProt describes a probable calcium-dependent phospholipid-binding protein with no transmembrane segment, which is compatible with membrane-associated staining (UniProt Q86YQ8: function and topology). The HPA tissue profile is Approved, with medium consistency between staining and RNA data (HPA tissue IHC: reliability).
| Clear cytoplasmic staining, with some membrane-associated signal, in kidney tubule cells or hepatocytes. | This matches the reported compartments and two high-staining cell populations (HPA tissue IHC: cytoplasmic and membranous; high in kidney tubule cells and hepatocytes). Judge signal within the identified cells; neighbouring cells need not show equal intensity. |
| Strong staining appears confined to nuclei, with little cytoplasmic or membrane signal. | A nucleus-only result conflicts with the reported tissue pattern (HPA tissue IHC: cytoplasmic and membranous). Check morphology and the no-primary control, then review antibody specificity and detection before assigning a CPNE8 nuclear location. |
| The strongest signal sits in tonsil germinal center cells or ovarian stroma cells. | Those cell populations are reported as not detected (HPA tissue IHC: tonsil germinal center cells; ovarian stroma cells). Consider cross-reactivity or endogenous chromogen-producing activity, and check a no-primary section; this observation does not establish true CPNE8 expression. |
| Brown colour spreads across multiple compartments or extracellular areas without cell boundaries. | Indistinct staining is difficult to score against the reported cytoplasmic and membranous pattern (HPA tissue IHC: profile). Compare the no-primary section and review blocking, washes and chromogenic detection as general IHC background checks. |
| No staining is visible in a section containing identifiable kidney tubule cells. | The cell population is reported as high, so absence warrants a technical check (HPA tissue IHC: high in kidney tubule cells). Confirm tissue identity, inspect detection controls, and review the catalog antibody's IHC-P instructions before interpreting a negative sample. |
💡Expected CPNE8 appearanceCall a section positive when identifiable cells show convincing cytoplasmic and membranous chromogen, especially kidney tubule cells or hepatocytes reported as High (HPA tissue IHC: profile and levels); isolated nuclear colour, staining of reported not-detected cell populations, or diffuse background should prompt control checks rather than a positive call (HPA tissue IHC: compartment and cell-level observations).
| Cell-specific reference pattern | High staining is reported in adipocytes, cardiomyocytes, hepatocytes, kidney tubule cells and several glandular or epithelial populations (HPA tissue IHC: positive cells). Interpret each named cell population within its tissue; a whole-section average can hide the relevant signal. |
| Negative comparison cells | Glial cells in caudate, ovarian stroma cells and tonsil germinal center cells are reported as not detected (HPA tissue IHC: negative cells). They can help reveal unexpected staining, but a result in one named population does not make its entire tissue a universal negative control. |
| Membrane association | The reported membranous pattern is compatible with probable calcium-dependent phospholipid binding despite the absence of a transmembrane segment (HPA tissue IHC: profile; UniProt Q86YQ8: function and topology). Do not require a sharp, exclusively membrane-bound outline. |
| Confidence and antibody scope | The tissue profile is Approved with medium staining-to-RNA consistency, and antibody HPA038600 is IHC Approved (HPA tissue IHC: reliability; HPA antibodies: HPA038600). These designations support a reference pattern, while discordant results still need controls; no IHC Enhanced designation is supplied. |
| Isoforms and epitope | UniProt lists 2 isoforms (UniProt Q86YQ8: isoforms). The supplied record gives no antibody epitope, so it cannot establish whether the catalog antibody detects both isoforms or whether isoforms differ in IHC appearance. |
| IF/ICC evidence boundary | HPA supplies no ICC-IF image-bearing cell lines and no main subcellular location (HPA subcellular: ICC-IF record). Its tissue IHC compartment pattern can guide a question for IF/ICC, but does not validate an IF/ICC staining result. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in an expected high-staining cell population. | The run may have failed, or the population may be misidentified; kidney tubule cells and hepatocytes are reported high (HPA tissue IHC: positive cells). | Verify morphology and detection controls. Review the catalog antibody's IHC-P protocol, including its stated retrieval and dilution, before changing conditions; no settings are supplied here. |
| Only nuclei stain strongly. | This disagrees with the reported cytoplasmic and membranous profile (HPA tissue IHC: profile). | Inspect the no-primary control and repeat with the IHC-validated antibody's instructions. Score a nuclear-only result as unresolved until specificity is supported. |
| Unexpected colour appears in germinal center cells or ovarian stroma cells. | These cells are reported as not detected (HPA tissue IHC: negative cells); cross-reactivity or endogenous activity is possible. | Compare no-primary and positive-control sections. For chromogenic IHC, check the general peroxidase-blocking and detection steps before attributing the colour to CPNE8. |
| Diffuse brown background obscures cell boundaries. | Nonspecific binding, insufficient washing or endogenous detection activity can obscure localisation (general IHC practice). | Check the no-primary control, blocking and washes; review detection chemistry and titrate antibody under the catalog IHC-P instructions. Reassess only when cells are distinguishable. |
| Membrane colour is present but lacks a crisp continuous rim. | CPNE8 has no transmembrane segment, while HPA reports a membranous component (UniProt Q86YQ8: topology; HPA tissue IHC: profile). | Evaluate membrane-associated colour together with cytoplasmic staining and cell morphology. Avoid requiring a transmembrane-protein appearance; compare a known-positive cell population. |
| Can the tissue IHC result serve as an IF/ICC positive pattern? | HPA lists no ICC-IF image-bearing cell lines or main location (HPA subcellular: ICC-IF record). | Use the tissue IHC pattern only as a starting hypothesis. Consult the separate IF/ICC guide and require IF/ICC-specific controls before interpreting fluorescent localisation. |
Experiment evidence
IHC & IF images showing CPNE8 staining
A15136-2 · IHCImmunohistochemistry analysis of paraffin-embedded human lung carcinoma tissue, using CPNE8 Antibody. The picture on the right is blocked wi
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000139117-CPNE8/tissue/cerebral+cortex#imid_9560885
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000139117-CPNE8/tissue/colon#imid_9551886
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000139117-CPNE8/tissue/liver#imid_9551879
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000139117-CPNE8/tissue/kidney#imid_9551896
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CPNE8 IHC & IF
🧪Run kidney first: tubular cells should stain (HPA: High in kidney cells in tubules). Use ovarian stroma as the biological negative (HPA: Not detected in ovarian stroma cells); on the kidney slide, cells without specific staining should show only background chromogen, without assuming every nontubular cell is CPNE8-negative.
Positive control tissue: Adipose tissue (Adipocytes, HPA High)
Negative control tissue: Caudate (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for CPNE8; derive a cell-line control from the positive tissue's cell type (Adipocytes) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species and clonality (standard IHC control practice). Use a CPNE8 knockout specimen if available, or a peptide-block control as shown for the catalog antibody (selected tissue-IHC caption: peptide block).
For kidney, check endogenous peroxidase and, if using biotin-based detection, endogenous biotin in tubular cells (standard IHC control practice).
⚠️Feasibility: A target-specific fixation window and the effect of fixation on CPNE8 staining are unreported in the supplied evidence; the selected paraffin-section caption does not state a fixative (selected tissue-IHC caption). CPNE8-specific retrieval requirements and whether frozen sections or IF are easier are also unreported. In kidney, endogenous biotin or peroxidase can mimic tubular staining if the detection system does not control for them (standard IHC practice).
HPA tissue IHC evidence for CPNE8
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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | High | Protein (IHC) | HPA → |
| Kidney | Cells in tubules | High | Protein (IHC) | HPA → |
Section 3
Advanced CPNE8 IHC Tips
Troubleshoot CPNE8 staining in paraffin sections by checking retrieval, cell compartment, controls, and scoring before interpreting chromogenic signal.
What retrieval should I start with when CPNE8 staining is weak?
Start with citrate buffer at pH 6.0 for heat-induced epitope retrieval at 95–98 °C for 20 min (page retrieval rule: cytoplasmic / membrane antigen). Allow sections to cool in the retrieval buffer, then keep heating and cooling conditions consistent across slides (standard IHC practice). Compare the weak section with a kidney tubule control, where CPNE8 staining is reported as high (HPA: High in kidney tubule cells). If signal remains weak, test a longer retrieval time on matched sections while watching for tissue damage and increased background (standard IHC practice).
Could fixation explain variable CPNE8 staining between paraffin sections?
Target-specific fixation sensitivity is unknown: the selected CPNE8 image identifies paraffin-embedded lung carcinoma but does not state its fixative (caption: A15136-2). For a controlled IHC comparison, record fixation conditions and process matched samples consistently; 10% neutral buffered formalin is a conventional tissue fixative (standard IHC practice). Compare sections of similar thickness and run them through the same pH 6.0 citrate retrieval cycle of 20 min (page retrieval rule: cytoplasmic / membrane antigen). If staining differs, assess morphology and control staining before assigning the difference to CPNE8 abundance or fixation (standard IHC practice).
Should CPNE8 stain the membrane, cytoplasm, or both?
Assess cytoplasmic and membranous signal separately because both patterns are reported across several tissues (HPA: cytoplasmic and membranous expression). UniProt provides no annotated CPNE8 subcellular location and lists no transmembrane segment, so an exclusively membrane-bound interpretation needs further validation (UniProt Q86YQ8: subcellular annotation and topology). In kidney, identify tubule cells before scoring their staining, because that is the reported high-staining population (HPA: High in kidney tubule cells). Use the same compartment definitions and a 0–3 intensity scale throughout the IHC comparison, and flag nuclear-only staining for control review (standard IHC scoring practice; HPA: cytoplasmic and membranous expression).
How do unknown epitope and splice variants affect CPNE8 IHC interpretation?
CPNE8 has 2 reported isoforms, while the supplied antibody caption does not identify its epitope or establish isoform coverage (UniProt Q86YQ8: isoforms; caption: A15136-2). Its mapped regions include C2 domains at residues 1–133 and 142–265, plus a VWFA domain at 309–510 (UniProt Q86YQ8: domains). The image includes staining blocked with synthesized peptide, which supports a peptide-competition check but does not identify the recognized isoform (caption: A15136-2). If isoform specificity matters, obtain the immunogen sequence, compare it with both isoforms, and interpret residual tissue staining with matched IHC controls (standard epitope-validation practice).
How can I adapt the CPNE8 IHC assessment to multiplex IF?
Treat multiplex IF as a separate validation exercise, since the supplied subcellular record lists no cell lines with CPNE8 ICC/IF images (HPA: subcellular record). Pair CPNE8 with a marker for the expected cell population, such as kidney tubule cells, and check whether their signals occupy the same cells (HPA: High in kidney tubule cells; standard multiplex IF practice). Choose a far-red fluorophore when the tissue shows strong shorter-wavelength autofluorescence, and include single-stain controls for spectral bleed-through (standard IF practice). Permeabilise when testing a cytoplasmic epitope, but establish the antibody epitope's accessibility experimentally because its location is unspecified (HPA: cytoplasmic and membranous expression; caption: A15136-2; standard IF practice).
How do I distinguish CPNE8 signal from chromogenic background?
Examine no-primary controls alongside stained sections to identify detection-system staining, and apply a peroxide block before peroxidase-based DAB detection (standard IHC practice). The selected image includes a synthesized-peptide blocking comparison, so use that exact antibody and peptide pairing when available to assess competing signal (caption: A15136-2). Compare suspected background with kidney tubule staining and with germinal center cells reported as undetected, while accounting for tissue-specific differences (HPA: High in kidney tubule cells; Not detected in tonsil germinal center cells). Reduce excessive primary or chromogen exposure through controlled titration, and inspect section edges and damaged areas separately from intact tissue (standard IHC practice).
What should I measure when comparing CPNE8 across IHC sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, since reported CPNE8 staining can be cytoplasmic or membranous (HPA: cytoplasmic and membranous expression). For intact target cells, record percent positive and intensity from 0–3; an H-score sums intensity-weighted percentages and spans 0–300 (standard IHC scoring practice). For sparse populations, report positive cells per mm² of viable tissue and state the threshold used to call a cell positive (standard quantitative IHC practice). Normalise to the number of eligible cells or viable compartment area, and keep retrieval, detection, and image acquisition consistent across sections (standard quantitative IHC practice).
When is an unexpected CPNE8 staining pattern likely to be artefactual?
Check whether signal follows the reported cytoplasmic or membranous pattern and falls in the cell population being evaluated (HPA: cytoplasmic and membranous expression). Kidney tubule cells provide a reported high-staining reference, whereas tonsil germinal center cells are reported as undetected; these are useful comparison populations, not absolute specificity tests (HPA: High in kidney tubule cells; Not detected in tonsil germinal center cells). Treat nuclear-only signal, strong section-edge staining, and staining confined to necrotic areas as reasons to inspect controls and morphology (HPA: cytoplasmic and membranous expression; standard IHC practice). Review no-primary and peroxide-block controls for endogenous enzyme signal before interpreting DAB deposits as CPNE8 (standard chromogenic IHC practice).
Boster reagents
Best CPNE8 / Copine-8 IHC Antibodies
A15136-2 has a paraffin-section human lung carcinoma IHC image (catalog image caption) and lists IF plus human, mouse and rat reactivity (catalog applications and reactivity); no IF image is supplied (catalog images).
Real IHC data
Anti-Copine 8 CPNE8 Antibody
Cat # A15136-2
A15136-2 will render with its human lung carcinoma paraffin-section IHC image, including a peptide-blocked comparison (catalog image caption). It lists IHC and IF applications and human, mouse and rat reactivity (catalog applications and reactivity); no IF image is supplied (catalog images).
Which to pick: Choose A15136-2 for tissue IHC: its image shows a paraffin section of human lung carcinoma (catalog image caption), but the fixative is unreported (catalog image caption). For IF, A15136-2 lists the application (catalog applications); ICC validation and clonality are unreported (catalog payload). For cross-species planning, A15136-2 lists human, mouse and rat reactivity (catalog reactivity), while its supplied IHC image documents human tissue only (catalog image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q86YQ8 (CPNE8_HUMAN, Copine-8).
- Human Protein Atlas. CPNE8 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. CPNE8 subcellular location (ICC-IF): Highest expression in RPTEC/TERT1: 61.8 nTPM.
- Human Protein Atlas. CPNE8 antibody validation summary (1 antibodies).
- CPNE8 Promotes Gastric Cancer Metastasis by Modulating Focal Adhesion Pathway and Tumor Microenvironment. International journal of biological sciences 2022 — PMC9379401.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:16541075 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CPNE8 (Copine-8). Expected localisation 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: A15136-2 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Caudate. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung carcinoma tissue; fixative not specified (datasheet A15136-2); 2. Fixation: Image fixative and duration unreported (datasheet A15136-2); 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-CPNE8, 1:100-1:300 (datasheet A15136-2); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining shows medium consistency with RNA data (HPA tissue IHC); Isoform / epitope: 2 isoforms ; epitope coverage is unknown (UniProt); Regulation: Expression regulation is unreported (UniProt). Evidence: UniProt Q86YQ8, HPA tissue IHC · Approved, HPA cell-line RNA · Highest expression in RPTEC/TERT1: 61.8 nTPM, Datasheet A15136-2, PMC9379401. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CPNE8/immunohistochemistry-ihc-guide.