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CBX1 / Chromobox protein homolog 1 · IHC design guide
Design Immunohistochemistry for CBX1
Plan paraffin-section CBX1 IHC around widespread nuclear staining (HPA tissue IHC). The catalog antibody has an IHC dilution range of 2–5 μg/ml (datasheet A04206-2); keep fixation consistent when comparing nuclear signal.
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CBX1 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 | Nuclear staining observed (HPA tissue IHC) | |
| Staining pattern | Nuclear staining across many tissue cell types (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A04206-2) | |
| Positive control | Bone marrow+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A04206-2) | |
| Caveat | Mitotic chromosomes may lack bound CBX1 (UniProt) | |
| Regulation | Broad adult and embryonic expression (UniProt) | |
| Isoform / epitope | No isoforms; one 1–185 chain for epitope mapping (UniProt) |
Section 1
Recommended CBX1 IHC & IF Protocols
The catalog antibody has an IHC-P protocol (datasheet A04206-2). The published protocols below cover HCC tissue microarrays (PMC11461582) and DLBCL sections (PMC10331996).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A04206-2) |
| Fixation | Image fixative and duration unreported (datasheet A04206-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A04206-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A04206-2) |
| Primary antibody | Rabbit anti-CBX1, 2-5 μg/ml (datasheet A04206-2) |
| Primary incubation | Overnight at 4 °C (datasheet A04206-2) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A04206-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | CBX1-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A04206-2); the DLBCL protocol also uses microwave EDTA retrieval (PMC10331996).
Section 2
What Is the Expected CBX1 Staining Pattern?
CBX1 should stain nuclei across many cell types in paraffin sections: UniProt places it in the nucleus and reports expression in all adult and embryonic tissues (UniProt P83916). HPA describes ubiquitous nuclear expression with high consistency between antibody staining and RNA data (HPA tissue IHC: Supported). CBX1 has no transmembrane segment, so membrane staining is not an expected target pattern (UniProt P83916 topology).
| Nuclear staining in bronchial respiratory epithelium and bone marrow hematopoietic cells. | This agrees with HPA's High staining in both named cell populations (HPA tissue IHC). Judge the result by nuclear location as well as intensity: strong color outside nuclei does not establish CBX1 detection (UniProt P83916; general IHC practice). |
| Predominantly cytoplasmic or membrane staining, with little nuclear signal. | The compartment conflicts with UniProt's nuclear localization and HPA's ubiquitous nuclear IHC profile (UniProt P83916; HPA tissue IHC). Check whether pigment, detection deposits, or nonspecific antibody binding explains the color before scoring it as CBX1 (general IHC practice). |
| Color appears only in an unexpected cell population while expected nuclei remain unstained. | Consider cross-reactivity or endogenous detection activity, particularly if a named HPA-positive population on the same slide is blank (HPA tissue IHC; general IHC practice). HPA reports ubiquitous expression and supplies no negative cell population, so cell identity alone cannot prove a false positive (HPA tissue IHC). |
| A diffuse haze covers tissue and obscures nuclear boundaries. | This is uninterpretable background rather than a convincing compartment-specific result (general IHC practice). Compare the no-primary control and review blocking, washes, antibody concentration, and chromogen development; none of those workflow checks establishes a CBX1-specific fixation effect (general IHC practice). |
| No nuclear signal appears in an adequately preserved known-positive tissue. | Bone marrow hematopoietic cells, bronchial respiratory epithelium, and several other listed populations show High HPA IHC staining (HPA tissue IHC). A blank result calls for review of tissue quality, retrieval, primary antibody, and detection controls; the supplied sources do not identify which step failed (general IHC practice). |
💡Expected CBX1 appearanceCall a section positive when nuclei stain in the relevant cells, with High staining plausible in HPA-listed populations; isolated cytoplasmic, membrane, or diffuse color without corresponding nuclear signal is suspect (HPA tissue IHC; UniProt P83916; general IHC practice).
| Cell population and tissue | HPA reports ubiquitous nuclear expression and High IHC staining in hematopoietic, respiratory epithelial, glial, granular-layer, glandular, and endothelial populations at the specified sites (HPA tissue IHC). It lists no negative tissues, so these data support positive controls but not a tissue-based negative control (HPA tissue IHC). |
| Cell-cycle context | UniProt notes that CBX1 is unassociated with chromosomes during mitosis (UniProt P83916 subcellular annotation). Do not require a mitotic chromosome staining pattern to match interphase nuclei; that annotation does not predict that an entire mitotic cell must be chromogen-negative (UniProt P83916; general IHC interpretation). |
| Antibody validation | The listed CAB012265 antibody has Supported IHC and ICC status; HPA071387 has Supported ICC status but no listed IHC status (HPA antibodies). HPA's tissue profile is Supported through consistency with RNA expression, which supports the broad nuclear pattern without proving every individual stained structure is specific (HPA tissue IHC). |
| IF/ICC question: what localization should be checked? | HPA reports supported nucleoplasmic and nuclear-body localization by ICC-IF (HPA subcellular). This is a localization cross-check for the separate IF/ICC guide, not an IHC protocol or a requirement that individual nuclear bodies be resolved by chromogenic paraffin IHC (HPA subcellular; general IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| A known-positive section has no nuclear staining. | The result conflicts with HPA's High staining in named populations, but the evidence does not identify a CBX1-specific failure mechanism (HPA tissue IHC). | Confirm the expected cells are present, then check retrieval, primary-antibody incubation, and detection with suitable run controls (general IHC practice). |
| Strong cytoplasmic or membrane color dominates the slide. | That distribution conflicts with the reported nuclear location and lack of a transmembrane segment (UniProt P83916; HPA tissue IHC). | Compare a no-primary control and inspect for pigment or detection deposits; score CBX1 only where a credible nuclear pattern is present (general IHC practice). |
| Only scattered unexpected cells stain while the expected population is blank. | Cross-reactivity or endogenous detection activity is possible; HPA provides no negative cell population that would settle the interpretation by identity alone (HPA tissue IHC; general IHC practice). | Check the no-primary control and whether the suspect color shares the expected nuclear compartment; compare with a known-positive section (general IHC practice). |
| Diffuse color makes nuclei hard to distinguish. | Background from detection or insufficient washing can obscure localization, without establishing anything about CBX1 abundance (general IHC practice). | Review blocking, washes, antibody concentration, and chromogen development against the no-primary control; interpret only clearly localized nuclear staining (general IHC practice). |
| A mitotic cell lacks staining on condensed chromosomes. | CBX1 is reported as unassociated with chromosomes during mitosis (UniProt P83916 subcellular annotation). | Assess the surrounding interphase nuclei and the overall control pattern before treating mitotic chromosome appearance as an assay failure (UniProt P83916; general IHC practice). |
| ICC-IF nuclear bodies are visible, but distinct bodies are not apparent in IHC. | Nuclear-body localization is supported in ICC-IF; the supplied HPA IHC profile describes ubiquitous nuclear expression without requiring resolvable bodies (HPA subcellular; HPA tissue IHC). | Use the nuclear compartment and expected positive cells to judge the chromogenic section; consult the separate IF/ICC guide for its imaging workflow (HPA tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing CBX1 staining
A04206-2 · IHCIHC analysis of CBX1/HP1 beta using anti-CBX1/HP1 beta antibody (A04206-2). CBX1/HP1 beta was detected in a paraffin-embedded section of hum
A04206-2 · IHCIHC analysis of CBX1/HP1 beta using anti-CBX1/HP1 beta antibody (A04206-2). CBX1/HP1 beta was detected in a paraffin-embedded section of hum
A04206-2 · IFIF analysis of CBX1/HP1 beta using anti-CBX1/HP1 beta antibody (A04206-2). CBX1/HP1 beta was detected in an immunocytochemical section of CA
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000108468-CBX1/tissue/cerebral+cortex#imid_3065840
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000108468-CBX1/tissue/colon#imid_3065774
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000108468-CBX1/tissue/liver#imid_3065759
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000108468-CBX1/tissue/kidney#imid_3065760
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB012265; green = CBX1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB012265; green = CBX1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CBX1 IHC & IF
🧪Run bone marrow first and expect staining in hematopoietic cells (HPA: High in hematopoietic cells). HPA detects CBX1 in all 45 scored tissues, so there is no supported negative tissue or established CBX1-negative cell population within the positive slide; use no-primary and isotype controls to judge background staining (HPA: detected in all 45 scored tissues; standard IHC practice).
Positive control tissue: Bone marrow (Hematopoietic cells, HPA High)
Negative control tissue: None in HPA: CBX1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CBX1 in A-431, U-251MG, U2OS, SH-SY5Y, SuSa, with annotated localisation: Nucleoplasm (supported), Nuclear bodies (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a rabbit IgG isotype control matched to the primary antibody’s clonality; use CBX1 knockout material or a peptide block, if available, as a biological specificity control (selected-SKU caption: rabbit primary; standard IHC practice). In bone marrow, block endogenous peroxidase and check for endogenous biotin signal with the caption’s avidin–biotin DAB detection method (HPA: bone marrow positive tissue; selected-SKU caption: SABC with DAB; standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). That caption reports heat-mediated retrieval in EDTA at pH 8.0, but does not establish whether retrieval is required for every specimen (selected-SKU caption: EDTA retrieval). The supplied evidence does not establish that frozen-section IHC or IF is easier; bone marrow myeloid cells can contribute endogenous peroxidase background in chromogenic IHC (standard IHC practice).
HPA tissue IHC evidence for CBX1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — High 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 |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: CBX1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced CBX1 IHC Tips
Troubleshoot CBX1 staining in paraffin section IHC by checking nuclear localisation, processing conditions, controls, and cell specific scoring.
Which retrieval conditions should I start with for CBX1 paraffin IHC?
Use heat mediated antigen retrieval in EDTA at pH 8.0 for CBX1 paraffin IHC (datasheet A04206-2). The selected tissue image used that retrieval before an overnight incubation at 4°C with 2 μg/ml primary antibody (datasheet A04206-2). If nuclear staining is weak, compare controlled heating durations on adjacent sections while holding antibody concentration and detection conditions constant (standard IHC practice). Check tissue architecture and nuclear counterstain alongside signal, since excessive retrieval can make interpretation difficult (standard IHC practice). Include a known nuclear positive tissue section in each comparison; widespread nuclear expression makes an entirely blank run suspect (HPA: ubiquitous nuclear expression).
How should I assess whether fixation is affecting CBX1 staining?
The selected paraffin section caption does not report a fixative, so CBX1 sensitivity to any particular fixation method or duration is unknown (datasheet A04206-2). Record the fixative, fixation duration, section age, and processing history for each specimen, then compare sections under the same retrieval and detection conditions (standard IHC practice). Use a matched, consistently processed positive control to distinguish a specimen processing problem from a failed staining run (standard IHC practice). Do not infer fixation tolerance from the reported nuclear tissue distribution or from CBX1 sequence features (HPA: ubiquitous nuclear expression; UniProt P83916). If signal differs between batches, review processing records before changing antibody concentration (standard IHC practice).
Where should convincing CBX1 staining appear in a paraffin section?
Score convincing CBX1 staining primarily in nuclei, consistent with its annotated nuclear location and the reported ubiquitous nuclear tissue pattern (UniProt P83916; HPA: tissue IHC). Nuclear bodies or uneven intranuclear staining can be plausible, although that finer pattern comes from subcellular imaging rather than the selected chromogenic tissue image (HPA: subcellular). Do not require staining on mitotic chromosomes: CBX1 is reported to be unassociated with chromosomes during mitosis (UniProt P83916). Compare cells within intact, well counterstained areas before calling diffuse cytoplasmic DAB a positive result (standard IHC practice; UniProt P83916: nucleus). Record nuclear intensity and the proportion of stained cells separately (standard IHC practice).
How do epitope uncertainty and CBX1 domains affect interpretation?
No alternative isoforms are listed for CBX1, and the record places a chromo domain at residues 21–79 and a chromoshadow domain at 117–175 (UniProt P83916). The selected tissue caption does not identify the antibody epitope, so a change in staining cannot be assigned to either domain (datasheet A04206-2). Reported phosphorylation includes Ser89, Ser91, and Ser175, but the supplied evidence does not establish that these modifications alter this antibody’s tissue staining (UniProt P83916; datasheet A04206-2). If an unexpected pattern persists, compare an independent epitope antibody and matched controls before attributing it to epitope masking or cross reactivity (standard IHC practice). Keep conclusions at the observed nuclear staining level (UniProt P83916: nucleus).
How should I check CBX1 in multiplex IF alongside this IHC result?
Treat IF/ICC as a separate assay: the selected antibody evidence describes chromogenic staining of a paraffin section, without reporting its fixative or an IF protocol (datasheet A04206-2). In a multiplex experiment, pair CBX1 with a validated marker for the cell population being examined, and use a nuclear counterstain to assess nuclear overlap (standard IF practice; UniProt P83916: nucleus). Choose fluorophores after checking tissue autofluorescence in each channel, favoring a spectrally separated, longer wavelength signal where background is lower (standard IF practice). Because CBX1 is nuclear and has no transmembrane segment, establish permeabilisation that permits antibody access to nuclei without disrupting them (UniProt P83916; standard IF practice). Assess nucleoplasmic and nuclear body patterns against controls (HPA: subcellular).
What should I change when CBX1 IHC shows diffuse background?
First separate true nuclear staining from diffuse cytoplasmic or extracellular DAB, using the counterstain to identify intact nuclei (UniProt P83916: nucleus; standard IHC practice). The selected tissue image used 10% goat serum blocking, 2 μg/ml primary antibody, a biotinylated secondary, and DAB development (datasheet A04206-2). Run a no primary control and inspect endogenous peroxidase or biotin associated signal before increasing blocking or reducing primary concentration (standard IHC practice). If background tracks section edges or damaged areas, compare intact central regions and review washing and chromogen development across the run (standard IHC practice). Preserve a positive nuclear control while adjusting one condition at a time (HPA: ubiquitous nuclear expression; standard IHC practice).
How should I quantify CBX1 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and intact tissue region before scoring, because CBX1 nuclear staining occurs across many tissues (HPA: ubiquitous nuclear expression). An H score can combine the percentage of nuclei at each intensity from 0–3; alternatively, report the percentage of positive nuclei with a prespecified threshold (standard IHC practice). Normalise counts to the number of evaluable nuclei in the same cell population, or express positive cell density per mm² of analysed tissue (standard IHC practice). Apply identical retrieval, exposure or scan settings, segmentation rules, and exclusion criteria across samples (standard IHC practice). Record necrotic and edge regions separately rather than including them in the denominator (standard IHC practice).
How can I distinguish genuine CBX1 positivity from staining artefact?
A credible positive call combines staining in intact nuclei with a clean no primary control, consistent with CBX1’s nuclear annotation and the reported tissue pattern (UniProt P83916; HPA: tissue IHC; standard IHC practice). High nuclear staining is reported in several cell populations, including bone marrow hematopoietic cells and bronchial respiratory epithelial cells, so cell identity matters when interpreting a mixed section (HPA: High in hematopoietic cells; HPA: High in respiratory epithelial cells). Treat predominantly cytoplasmic staining, section edge enhancement, and staining confined to necrotic areas as reasons to investigate artefact (UniProt P83916: nucleus; standard IHC practice). Check no primary and peroxidase controls when DAB appears outside nuclei, particularly with enzyme based detection (standard IHC practice). Interpret intensity only within comparable, well preserved regions (standard IHC practice).
Boster reagents
Best CBX1 / Chromobox protein homolog 1 IHC Antibodies
A04206-2 has IHC images from human lung cancer, human thyroid papillary carcinoma, mouse intestines, and rat brain paraffin sections (catalog IHC captions), plus IF/ICC data from CACO-2 cells (catalog IF caption).
Real IHC data
Anti-CBX1/HP1 beta Antibody ®
Cat # A04206-2
A04206-2 will render with its human lung cancer paraffin-section IHC figure (catalog IHC caption). Its additional IHC captions document human thyroid papillary carcinoma, mouse intestines, and rat brain; its IF caption documents CACO-2 cells (catalog IHC and IF captions).
Which to pick: Choose A04206-2 for tissue IHC on paraffin sections; its IHC figure used 2 μg/ml after heat retrieval in EDTA at pH 8.0 (catalog IHC figure caption). The same SKU supports IF/ICC in CACO-2 cells at 5 μg/ml (catalog IF caption). For cross-species IHC, its listed reactivity covers human, mouse, and rat (catalog reactivity), with paraffin-section images for each (catalog IHC captions); it is rabbit-hosted, its clonality is unreported, and the tissue fixative is unreported (catalog host and clone fields; catalog IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P83916 (CBX1_HUMAN, Chromobox protein homolog 1).
- Human Protein Atlas. CBX1 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. CBX1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm and nuclear bodies..
- Human Protein Atlas. CBX1 antibody validation summary (2 antibodies).
- CBX1 is involved in hepatocellular carcinoma progression and resistance to sorafenib and lenvatinib via IGF-1R/AKT/SNAIL signaling pathway. Hepatology international 2024 — PMC11461582.
- CBX1 as a Prognostic Biomarker and Therapeutic Target in Liver Hepatocellular Carcinoma: Insight into DNA Methylation and Non-Coding RNA Networks from Comprehensive Bioinformatics Analysis. Medicina (Kaunas, Lithuania) 2025 — PMC12195192.
- CBX1 Indicates Poor Outcomes and Exerts Oncogenic Activity in Hepatocellular Carcinoma. Translational oncology 2018 — PMC6074001.
- An integrative bioinformatics investigation and experimental validation of chromobox family in diffuse large B-cell lymphoma. BMC cancer 2023 — PMC10331996.
- PubMed PMID:9169582 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:10460410 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CBX1 (Chromobox protein homolog 1). Expected localisation Nuclear staining observed (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A04206-2). Validated IHC antibody: A04206-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A04206-2); 2. Fixation: Image fixative and duration unreported (datasheet A04206-2); 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 retrieval: EDTA pH 8.0 (datasheet A04206-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A04206-2); 8. Primary antibody: Rabbit anti-CBX1, 2-5 μg/ml (datasheet A04206-2); 9. Primary incubation: Overnight at 4 °C (datasheet A04206-2). Watch for: Fixation: Keep fixation consistent (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A04206-2); Caveat: Mitotic chromosomes may lack bound CBX1 (UniProt); Isoform / epitope: No isoforms; one 1–185 chain for epitope mapping (UniProt); Regulation: Broad adult and embryonic expression (UniProt). Evidence: UniProt P83916, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm and nuclear bodies., Datasheet A04206-2, PMC11461582, PMC10331996. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CBX1/immunohistochemistry-ihc-guide.