CUL4B / Cullin-4B · IHC design guide

Design Immunohistochemistry for CUL4B

Plan CUL4B paraffin-section IHC around its general nuclear pattern (HPA tissue IHC). Adrenal and epididymal glandular cells offer high-signal references (HPA tissue IHC); the catalog antibody lists 0.5–1 μg/ml for IHC (datasheet).

Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use

Immunohistochemistry protocol sheet for CUL4B (IHC for CUL4B): expected localisation Predominantly nuclear in tissue; cytoplasmic location is also annotated (HPA tissue IHC; UniProt), antibody PA1233, validated IHC image, and IHC protocol steps — Printable **CUL4B** IHC protocol sheet — expected localisation Predominantly nuclear in tissue; cytoplasmic location is also annotated (HPA tissue IHC; UniProt), antibody PA1233, controls and protocol steps. Open the full CUL4B IHC guide →

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CUL4B 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	Predominantly nuclear in tissue; cytoplasmic location is also annotated (HPA tissue IHC; UniProt)
	Staining pattern	General nuclear staining across cell types (HPA tissue IHC)
	Antigen retrieval	Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen)
	Positive control ⓘ	Adrenal gland+4 more · see all
	Negative control ⓘ	Adipose tissue+4 more · see all

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Keep fixation consistent across sections (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 PA1233)
	Caveat	Adipocytes may lack signal despite the general nuclear pattern (HPA tissue IHC)
	Regulation	No specific expression regulator annotated (UniProt)
	Isoform / epitope	3 isoforms; no transmembrane segment; epitope coverage unknown (UniProt)

Section 1

Recommended CUL4B IHC & IF Protocols

The catalog antibody protocol appears alongside 4 published CUL4B IHC protocols (PMC6536945; PMC3351389; PMC7335446; PMC6418142).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Tissue sections; selected-image fixative not specified (standard IHC workflow)
Fixation	Image fixative and duration unreported (datasheet PA1233); 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-CUL4B, 0.5-1μg/ml (datasheet PA1233)
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	CUL4B-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: General nuclear expression. No signal in the no-primary control.

💡Decision noteStart with Tris-EDTA pH 9.0 at 95–98 °C for 20 min (page antigen retrieval rule); compare citrate retrieval where reported (PMC3351389; PMC7335446).

Section 2

What Is the Expected CUL4B Staining Pattern?

CUL4B should show predominantly nuclear staining in paraffin tissue sections (HPA: general nuclear expression; Enhanced reliability). Adrenal and epididymal glandular cells show high staining; bronchial respiratory epithelial cells and cerebral cortical neurons show medium staining (HPA: tissue IHC). Some cytoplasmic signal is biologically plausible (UniProt Q13620: nucleus and cytoplasm; no transmembrane segment), so interpret compartment together with cell type and controls.

What am I looking at on my slide?
Distinct nuclear stain in adrenal or epididymal glandular cells, with little staining in adjacent negative areas.	This fits an expected high positive result (HPA: adrenal and epididymal glandular cells, High; general nuclear expression). Judge intensity within the named cell population, since a tissue-level label does not mean every cell on the section must stain (HPA: cell-specific tissue IHC entries).
Predominantly cytoplasmic staining with weak or absent nuclei across a positive tissue section.	The compartment disagrees with the tissue IHC profile and warrants an artefact or specificity check (HPA: general nuclear expression). Cytoplasm alone is not proof of cross-reactivity: UniProt lists both cytoplasm and nucleus, with developmental redistribution reported in oocytes and early embryos (UniProt Q13620: subcellular location).
Strong staining in adipocytes or alveolar cells, especially when expected positive cells are unstained.	These cell populations are listed as not detected (HPA: adipose adipocytes; lung alveolar cells). Unexpected color may reflect cross-reactivity or endogenous chromogen-generating activity; assess a no-primary control and detection-system controls before assigning it to CUL4B (standard IHC practice).
Uniform haze over nuclei, cytoplasm, and tissue spaces, without clear cell boundaries.	A spatially diffuse deposit does not match the reported nuclear profile (HPA: general nuclear expression). Excess antibody, incomplete blocking, or detection background are possible general IHC causes; compare a no-primary control and reassess staining conditions (standard IHC practice).
No nuclear stain in adrenal or epididymal glandular cells despite an intact section.	A missing signal in an expected high population calls for an assay check (HPA: adrenal and epididymal glandular cells, High). Review antibody IHC validation and the run controls, then optimize general IHC steps such as retrieval and detection; this record does not establish CUL4B-specific fixation sensitivity (HPA: antibody validation; standard IHC practice).

💡Expected CUL4B appearanceCall a section positive when the expected glandular cells show distinct, predominantly nuclear high staining (HPA: adrenal gland or epididymis, High; general nuclear expression); diffuse deposit or dominant staining in HPA-listed negative cell types is a suspect positive (HPA: adipocytes and alveolar cells, Not detected; standard IHC practice).

How each factor affects the staining
Which tissue best anchors interpretation?	Adrenal or epididymal glandular cells provide reported high positives (HPA: tissue IHC). Adipocytes and lung alveolar cells are listed as not detected, useful comparison populations within a validated run, not universal guarantees of absent protein (HPA: tissue IHC).
How strong is the staining evidence?	The tissue profile has Enhanced reliability, described as high agreement between antibody staining and RNA expression (HPA: tissue IHC). HPA011880 has IHC Enhanced status, while CAB017786 is IHC Supported (HPA: antibody validation); validation status does not specify a working dilution or retrieval condition.
Could isoforms or protein processing change the call?	Three isoforms are listed, but no supplied epitope map establishes which an individual antibody detects (UniProt Q13620: isoforms). UniProt lists no signal peptide or propeptide and a 1–913 chain; do not infer secretion or shedding from this record (UniProt Q13620: processing).
Is a membrane pattern expected?	No transmembrane segment is annotated (UniProt Q13620: topology). A dominant membrane rim would therefore require independent validation; the observed tissue pattern is nuclear (HPA: tissue IHC). UniProt also lists a cullin neddylation region at residues 845–905, but this does not locate the antibody epitope (UniProt Q13620: domains).
What should IF/ICC show?	Mainly nucleoplasmic signal is reported, with an enhanced nucleoplasm assignment (HPA: subcellular ICC-IF). Use that as a compartment cross-check only; IF/ICC assay setup belongs to its own guide, and its image result does not prescribe an IHC paraffin protocol (HPA: subcellular ICC-IF).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Expected positive glands lack signal.	The run may have insufficient assay sensitivity; HPA reports high staining in adrenal and epididymal glandular cells (HPA: tissue IHC).	Confirm the antibody has IHC validation, then review positive-control performance, retrieval, antibody concentration, and detection using standard paraffin-IHC optimization (HPA: antibody validation; standard IHC practice). No CUL4B-specific fixation effect is supplied.
Signal is mainly cytoplasmic.	This departs from the general nuclear tissue profile, although cytoplasmic CUL4B is annotated (HPA: tissue IHC; UniProt Q13620: subcellular location).	Check nuclear counterstain alignment and the positive-control tissue, then compare staining with an independently validated antibody if available (standard IHC practice; HPA: IHC antibody validation). Avoid rejecting all cytoplasmic signal without considering the tissue and cell context.
Adipocytes or alveolar cells stain strongly.	Those cells are recorded as not detected; antibody cross-reactivity or endogenous detection activity is possible (HPA: tissue IHC; standard IHC practice).	Run a no-primary control and the appropriate enzyme or detection control, and inspect whether color follows the same cells (standard IHC practice). Treat an unexpected signal as unresolved until controls separate detection background from primary-antibody binding.
Every compartment has a faint brown haze.	The distribution lacks the reported nuclear emphasis; excess reagent or incomplete blocking may contribute (HPA: general nuclear expression; standard IHC practice).	Compare no-primary background, review blocking and washes, and titrate the primary antibody within the assay workflow (standard IHC practice). Score identifiable nuclei only after the diffuse background is reduced.
Only scattered weak nuclei appear in a nominally negative comparison.	A not detected HPA call applies to its named cell population and assay observation, not every cell in the tissue (HPA: cell-specific tissue IHC).	Identify the stained cell type before calling a contradiction; compare morphology, counterstain, and no-primary control (standard IHC practice). Record focal staining separately from the HPA-listed negative population.
The counterstain obscures a faint nuclear signal.	Overlapping nuclear color can make compartment scoring uncertain in chromogenic IHC (standard IHC practice).	Review the chromogen-only appearance or adjust counterstain strength in a repeat run (standard IHC practice). Interpret intensity against the expected high adrenal or epididymal glandular reference and the HPA general nuclear profile (HPA: tissue IHC).

Source: UniProt Q13620 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing CUL4B staining

PA1233 · IHCAnti-Cullin 4B antibody, PA1233, IHC(P) IHC(P): Zebrafish Body Tissue

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000158290-CUL4B/tissue/cerebral+cortex#imid_3298388

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000158290-CUL4B/tissue/colon#imid_3298306

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000158290-CUL4B/tissue/liver#imid_3298323

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000158290-CUL4B/tissue/kidney#imid_3298316

HPA · ICC-IF U-251MGHuman Protein Atlas immunofluorescence, U-251MG, antibody HPA011880; green = CUL4B, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

Real IHC / IF data behind the staining-pattern expectations in this section.

Sample controls for CUL4B IHC & IF

🧪Run adrenal gland first: its glandular cells should stain (HPA: High in adrenal gland glandular cells). Use adipose tissue as the negative tissue, focusing on adipocytes (HPA: Not detected in adipocytes); on the adrenal slide, use unstained nonglandular areas as background references, without treating them as validated CUL4B-negative cells (HPA: adrenal gland result specifies glandular cells).

Positive control tissue: Adrenal gland (Glandular cells, HPA High)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CUL4B in U-251MG, U2OS, A-431, KOLF2.1J, HeLa BAC 3316, HeLa , NIH 3T3, with annotated localisation: Nucleoplasm (enhanced) (HPA subcellular).

Technical controls: Include no-primary (secondary-only) and isotype controls matched to the primary antibody’s host species and clonality, plus CUL4B knockout material or a peptide-block control where the immunizing peptide is available (standard IHC practice). For chromogenic staining, block endogenous peroxidase and inspect the adrenal section for intrinsic pigment before scoring (standard IHC practice).

⚠️Feasibility: A target-specific fixation window and retrieval dependency are unreported in the supplied evidence; optimize antigen retrieval on pilot paraffin sections (standard IHC practice). The selected PA1233 zebrafish-body IHC(P) caption does not report a fixative (catalog caption: fixative not stated). The evidence does not establish whether frozen sections or IF are easier, or identify a CUL4B-specific adrenal artefact; ICC-IF images exist, but IF/ICC guidance belongs on its own page (HPA: subcellular ICC-IF images; catalog caption: IHC(P)).

HPA tissue IHC evidence for CUL4B

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — 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
Adrenal gland	Glandular cells	High	Protein (IHC)	HPA →
Epididymis	Glandular cells	High	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Medium	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	Medium	Protein (IHC)	HPA →
Cerebellum	Cells in granular layer	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Lung	Alveolar cells	Not detected	Protein (IHC)	HPA →
Ovary	Ovarian stroma cells	Not detected	Protein (IHC)	HPA →
Soft tissue	Peripheral nerve	Not detected	Protein (IHC)	HPA →

Section 3

Advanced CUL4B IHC Tips

Troubleshoot CUL4B staining in paraffin section IHC by checking nuclear signal, tissue controls and processing conditions before comparing samples.

How should I optimise retrieval when nuclear CUL4B staining is weak?

Start with Tris-EDTA at pH 9.0, heated to 95–98 °C for 20 min (page retrieval rule: nuclear antigen). Run matched sections with the same cooling, wash and chromogenic detection steps, then compare nuclear signal in adrenal glandular cells with low staining in adipocytes (HPA: High in adrenal glandular cells; Not detected in adipocytes). If staining remains weak, test a gentler retrieval condition on adjacent sections, changing only one variable at a time and recording tissue damage and background (standard IHC practice). Judge improvement by clearer nuclear staining, consistent with the reported general nuclear tissue pattern, rather than stronger diffuse colour (HPA: general nuclear expression).

Could fixation explain variable CUL4B staining between paraffin blocks?

CUL4B specific sensitivity to fixative type or fixation duration is unknown from the supplied evidence; the selected PA1233 tissue image does not report a fixative (PA1233 caption: fixative not stated). Record fixative, delay before fixation and processing history for each block before comparing chromogenic signal (standard IHC practice). When material permits, compare sections processed together, using the same pH 9.0 retrieval and 20 min heating so that fixation history is the main variable (page retrieval rule: nuclear antigen; standard IHC practice). Assess preserved morphology and nuclear staining in an expected positive cell population, while treating a negative result in a poorly preserved block as inconclusive (HPA: general nuclear expression; standard IHC practice).

Should CUL4B appear in nuclei or cytoplasm in tissue sections?

Prioritise nuclear staining when reading paraffin sections because the tissue profile reports general nuclear expression and the subcellular profile places CUL4B mainly in the nucleoplasm (HPA: tissue IHC profile; HPA: nucleoplasm enhanced). Cytoplasmic signal is biologically possible, since CUL4B is annotated in both cytoplasm and nucleus and has no transmembrane segment (UniProt Q13620: subcellular location and topology). Compare each compartment against adjacent cells, morphology and a matched negative control before calling weak cytoplasmic colour positive (standard IHC practice). Do not generalise the stage dependent oocyte distribution to every tissue: the reported nuclear to cytoplasmic shift concerns GV, MII, zygote and 2-cell stages (UniProt Q13620: subcellular location).

How can isoforms or epitope accessibility affect CUL4B IHC?

CUL4B has 3 annotated isoforms, so establish which sequence the IHC-validated antibody recognises before interpreting a missing signal as absent total CUL4B (UniProt Q13620: isoforms 1, 2 and 3; standard IHC practice). The supplied evidence does not map the catalog antibody epitope, and its detection of individual isoforms therefore remains unknown (supplied PA1233 caption: no epitope mapping). CUL4B also carries annotated phosphorylation sites near residues 49, 53, 100, 146 and 148, plus a cullin neddylation domain at 845–905 (UniProt Q13620: modified residues and domains). Document epitope mapping and validate specificity in the intended sections before attributing a staining difference to either modification or isoform expression (standard IHC practice).

How can IF help resolve an ambiguous CUL4B IHC pattern?

Use IF on a separate matched specimen to compare CUL4B with a marker for the cell population under study; the expected IHC pattern is generally nuclear (HPA: general nuclear expression; standard IF practice). Choose spectrally separated fluorophores and inspect an unstained section in each channel so tissue autofluorescence is distinguishable from specific signal (standard IF practice). Because CUL4B lacks a transmembrane segment and is mainly nucleoplasmic in the reported subcellular profile, optimise permeabilisation for access to an intracellular epitope while checking nuclear morphology (UniProt Q13620: topology; HPA: nucleoplasm enhanced; standard IF practice). Treat IF colocalisation as a localisation check and retain matched chromogenic IHC controls for claims about tissue staining (standard IHC/IF practice).

What causes diffuse brown background that obscures nuclear CUL4B?

First compare the stained section with a no primary control and inspect whether colour follows tissue edges, damaged areas or endogenous pigment rather than cell nuclei (standard chromogenic IHC practice; HPA: general nuclear expression). Include a peroxidase block before horseradish peroxidase and DAB detection, and confirm that the block reduces colour in the no primary control (standard chromogenic IHC practice). If background persists, optimise antibody concentration, incubation and washes on adjacent sections while keeping retrieval at pH 9.0 for 20 min constant initially (standard IHC practice; page retrieval rule: nuclear antigen). Preserve the condition that separates nuclear staining in expected positive cells from control background, rather than choosing the darkest section (HPA: High in adrenal glandular cells; standard IHC practice).

How should I score CUL4B across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and nuclear scoring rule before reviewing groups, because the reported tissue pattern is generally nuclear and varies by cell type (HPA: tissue IHC profile; standard IHC practice). For comparable sections, report the percentage of positive nuclei and an H-score from intensity grades 0–3, using the same threshold, exposure to chromogen and counterstain criteria throughout (standard IHC quantification practice). Normalise positive counts to evaluable nuclei in the defined compartment, or report positive nuclei per mm² when cell density itself matters (standard IHC quantification practice). Exclude necrotic or poorly preserved regions, and score matched positive and negative control sections with each batch (standard IHC practice).

When is a CUL4B positive stain convincing rather than artefactual?

A convincing chromogenic signal is reproducible in intact nuclei of the expected cell population, consistent with general nuclear tissue expression and mainly nucleoplasmic localisation (HPA: tissue IHC profile; HPA: nucleoplasm enhanced). Check a tissue cell population reported as high, such as adrenal glandular cells, alongside one reported as not detected, such as adipocytes, without treating either pattern as an absolute specificity test (HPA: High in adrenal glandular cells; Not detected in adipocytes; standard IHC practice). Diffuse extracellular colour, tissue edge accentuation, necrotic regions and colour remaining in a no primary control warrant investigation (standard chromogenic IHC practice). Evaluate endogenous peroxidase or pigment before attributing brown deposits to CUL4B, particularly when staining lacks a nuclear pattern (standard chromogenic IHC practice; HPA: general nuclear expression).

Boster reagents

Best CUL4B / Cullin-4B IHC Antibodies

The IHC-validated anti-CUL4B antibody has a zebrafish body tissue IHC(P) image (PA1233 image caption). The catalog lists Human, Mouse, Rat and Zebrafish reactivity (PA1233 catalog).

Real IHC data Anti-Cullin 4B antibody, PA1233, IHC(P) IHC(P): Zebrafish Body Tissue

Anti-Cullin 4B/CUL4B Antibody ®

Cat # PA1233

View product →

PA1233 is the sole rendering SKU; it lists IHC and WB applications and has a zebrafish body tissue IHC(P) image (PA1233 catalog; PA1233 image caption). Human, Mouse, Rat and Zebrafish reactivity is listed, while the supplied IHC image shows zebrafish tissue (PA1233 catalog; PA1233 image caption).

Which to pick: For tissue IHC, choose PA1233: its image caption identifies a zebrafish body tissue paraffin-section result, but does not report the fixative (PA1233 image caption). There is no supported IF/ICC pick because PA1233 has no listed IF application or IF image (PA1233 catalog). For cross-species planning, PA1233 is rabbit-host and lists Human, Mouse, Rat and Zebrafish reactivity; its pictured IHC result is zebrafish only (PA1233 catalog; PA1233 image caption).

Each figure is that product's own IHC / IF validation image from its datasheet.

References

UniProt Consortium. UniProt entry Q13620 (CUL4B_HUMAN, Cullin-4B).
Human Protein Atlas. CUL4B tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. CUL4B subcellular location (ICC-IF): Mainly localized to the nucleoplasm..
Human Protein Atlas. CUL4B antibody validation summary (4 antibodies).
CUL4B promotes aggressive phenotypes of HNSCC via the activation of the Wnt/β-catenin signaling pathway. Cancer medicine 2019 — PMC6536945.
Lack of Cul4b, an E3 ubiquitin ligase component, leads to embryonic lethality and abnormal placental development. PloS one 2012 — PMC3351389.
Cul4B promotes the progression of ovarian cancer by upregulating the expression of CDK2 and CyclinD1. Journal of ovarian research 2020 — PMC7335446.
CUL4B promotes prostate cancer progression by forming positive feedback loop with SOX4. Oncogenesis 2019 — PMC6418142.
PubMed PMID:14578910 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:17974005 — UniProt-cited evidence.