BZW2 / eIF5-mimic protein 1 · IHC design guide

Design Immunohistochemistry for BZW2

Plan chromogenic BZW2 IHC on paraffin sections using 2–5 μg/ml of the IHC-validated antibody as a starting range (datasheet A11832-1). Score cytoplasmic staining by cell type, using breast or gallbladder glandular cells as positive references and appendix glandular cells as a negative reference (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for BZW2 (IHC for BZW2): expected localisation Cytoplasmic staining in most tissues (HPA tissue IHC), antibody A11832-1, validated IHC image, and IHC protocol steps — Printable **BZW2** IHC protocol sheet — expected localisation Cytoplasmic staining in most tissues (HPA tissue IHC), antibody A11832-1, controls and protocol steps. Open the full BZW2 IHC guide →

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BZW2 Immunohistochemistry Experimental Design Guide

Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.

Must know before staining

	Expected localisation	Cytoplasmic staining in most tissues (HPA tissue IHC)
	Staining pattern	Variable cytoplasmic staining; high in some glandular cells (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A11832-1)
	Positive control ⓘ	Breast+4 more · see all
	Negative control ⓘ	Appendix+4 more · see all

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A11832-1)
	Caveat	Staining has medium concordance with RNA expression (HPA tissue IHC)
	Regulation	No staining regulator established (UniProt)
	Isoform / epitope	2 isoforms; check whether the epitope is shared (UniProt)

Section 1

Recommended BZW2 IHC & IF Protocols

The catalog antibody’s IHC-P protocol is paired with a published BZW2 IHC protocol for human HCC samples (PMC8317536).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human appendiceal adenocarcinoma tissue; fixative not specified (datasheet A11832-1)
Fixation	Image fixative and duration unreported (datasheet A11832-1); 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 A11832-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A11832-1)
Primary antibody	Rabbit anti-BZW2, 2-5 μg/ml (datasheet A11832-1)
Primary incubation	Overnight at 4 °C (datasheet A11832-1)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A11832-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	BZW2-positive staining in glandular cells of breast (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression with varying intensity in most tissues. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval, as specified for the catalog antibody (datasheet A11832-1).

Section 2

What Is the Expected BZW2 Staining Pattern?

BZW2 is a cytoplasmic protein with no transmembrane segment (UniProt Q9Y6E2). In paraffin-section IHC, expect cytoplasmic staining of the relevant cells, especially breast and gallbladder glandular cells and testicular Leydig cells, where staining is high (HPA tissue IHC). Intensity varies across tissues and cell types (HPA tissue IHC). HPA rates its tissue profile Enhanced, with medium consistency between staining and RNA data and external verification pending (HPA tissue IHC).

What am I looking at on my slide?
Cytoplasmic stain in breast or gallbladder glandular cells, or testicular Leydig cells.	This matches HPA's high staining in those cell types and UniProt's cytoplasmic localization (HPA tissue IHC; UniProt Q9Y6E2). Compare the named cell population, not the entire section, when judging a positive result.
A dominant nuclear signal, with little or no cytoplasmic stain.	Nuclear-dominant staining conflicts with the reported cytoplasmic IHC profile and UniProt localization (HPA tissue IHC; UniProt Q9Y6E2). Treat it as suspect and check controls and detection conditions before assigning it to BZW2 (standard IHC practice).
Strong stain in a cell population HPA lists as not detected, such as lung alveolar cells.	That differs from the reported result for that specific population (HPA tissue IHC). Cross-reactivity or endogenous detection activity is possible; examine an appropriate detection control before interpreting the stain (standard IHC practice). A negative HPA entry does not establish that every cell in the tissue is negative.
Diffuse color covers cells and surrounding section without a clear cytoplasmic pattern.	This obscures the compartment and cell-type pattern needed for interpretation (HPA tissue IHC; UniProt Q9Y6E2). Review blocking, washes, primary-antibody concentration and the detection control as general sources of background (standard IHC practice).
No visible stain in the expected cells of a breast, gallbladder or testis control.	HPA reports high staining in the named glandular or Leydig cells (HPA tissue IHC). Check that those cells are present, then assess the run's controls, retrieval and detection steps (standard IHC practice). A failed control leaves a negative test section uninterpretable.

💡Expected BZW2 appearanceCall a result concordant when the named HPA-positive cells show predominantly cytoplasmic staining at an intensity consistent with their reported level; nuclear-dominant stain or strong signal in an HPA-not-detected cell population is suspect (HPA tissue IHC; UniProt Q9Y6E2).

How each factor affects the staining
Tissue and cell-type choice	Breast and gallbladder glandular cells and testicular Leydig cells are high examples; colon glandular cells are medium, while appendix glandular cells are not detected (HPA tissue IHC). Specify the cell population when selecting and reading controls.
Breadth of tissue staining	HPA describes cytoplasmic expression at varying intensity in most tissues (HPA tissue IHC). Its not-detected entries apply to the listed cell populations, so a whole-tissue positive or negative call can hide the relevant result.
Strength of the tissue evidence	The tissue profile is Enhanced, yet staining and RNA show only medium consistency and external verification is pending (HPA tissue IHC). Use the pattern as an expectation to test, rather than proof of target specificity in a new specimen.
Antibody-specific validation	HPA lists IHC status as Approved for HPA022813 and Enhanced for HPA026709 (HPA antibodies). Those ratings differ by antibody; they do not automatically validate the catalog antibody or explain an unexpected stain.
Isoforms and processing	UniProt lists 2 isoforms and a 1–419 protein chain without a signal peptide or propeptide (UniProt Q9Y6E2). The supplied record gives no antibody epitope, so it cannot establish isoform-specific staining or predict an epitope-retrieval effect.
Q: Does the IF/ICC pattern match the IHC call?	A: HPA reports approved plasma-membrane, actin-filament and cytosol localization in ICC-IF (HPA subcellular). Those observations are assay-specific; use the tissue-IHC cytoplasmic profile to judge paraffin-section staining (HPA tissue IHC).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Expected positive cells are unstained.	The run may have failed at retrieval, primary staining or detection; the image alone cannot identify which step (standard IHC practice).	Confirm the named cells are present, inspect the positive control and verify the recorded IHC-P conditions before interpreting a negative result (HPA tissue IHC; standard IHC practice).
The section has widespread weak brown haze.	Nonspecific binding, insufficient washing or detection background can reduce contrast (standard IHC practice).	Review blocking and washes, then compare a primary-omission detection control. Score only cell-associated signal with a readable cytoplasmic pattern (standard IHC practice; HPA tissue IHC).
Nuclei dominate the stain.	That distribution disagrees with the reported cytoplasmic localization (UniProt Q9Y6E2; HPA tissue IHC). Its cause cannot be assigned from localization data alone.	Check the counterstain and detection control, then compare the suspect section with a known positive tissue stained in the same run (standard IHC practice; HPA tissue IHC).
Lung alveolar cells or appendix glandular cells stain strongly.	Those specific populations are reported as not detected, so the result needs scrutiny (HPA tissue IHC). Cross-reactivity or endogenous activity is possible (standard IHC practice).	Identify the stained cells carefully, inspect the detection control and compare with an HPA-high cell population before assigning BZW2 positivity (HPA tissue IHC; standard IHC practice).
Different cell types in one tissue show different intensities.	HPA reports varying intensity across tissues and cell populations (HPA tissue IHC). A section-wide score can therefore conceal the relevant cell-specific result.	Record compartment, cell identity and intensity separately; compare each population with its own HPA entry where available (HPA tissue IHC; standard IHC practice).
A new antibody gives a pattern unlike the HPA images.	HPA's IHC validation applies to its listed antibodies, with Approved and Enhanced statuses respectively (HPA antibodies). It does not establish the new antibody's specificity.	Check that antibody's documented IHC-P use and run appropriate positive and detection controls; treat discordant localization or cell-type staining as unresolved (standard IHC practice; HPA tissue IHC).

Source: UniProt Q9Y6E2 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing BZW2 staining

IHC analysis of BZW2 using anti-BZW2 antibody (A11832-1). BZW2 was detected in a paraffin-embedded section of human appendiceal adenocarcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml rabbit anti-BZW2 Antibody (A11832-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A11832-1 · IHCIHC analysis of BZW2 using anti-BZW2 antibody (A11832-1). BZW2 was detected in a paraffin-embedded section of human appendiceal adenocarcino

IHC analysis of BZW2 using anti-BZW2 antibody (A11832-1). BZW2 was detected in a paraffin-embedded section of human gastric adenocarcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml rabbit anti-BZW2 Antibody (A11832-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A11832-1 · IHCIHC analysis of BZW2 using anti-BZW2 antibody (A11832-1). BZW2 was detected in a paraffin-embedded section of human gastric adenocarcinoma t

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000136261-BZW2/tissue/cerebral+cortex#imid_6018720

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000136261-BZW2/tissue/colon#imid_6018662

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000136261-BZW2/tissue/liver#imid_6018647

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000136261-BZW2/tissue/kidney#imid_6018648

HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA026709; green = BZW2, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for BZW2 IHC & IF

🧪Run breast first and look for staining in glandular cells (HPA: High in breast glandular cells). Use appendix as a negative tissue and assess its glandular cells (HPA: Not detected in appendix glandular cells); on the breast slide, unstained background regions help reveal nonspecific signal, but other cell types are not established as BZW2-negative by the supplied HPA row.

Positive control tissue: Breast (Glandular cells, HPA High)

Negative control tissue: Appendix (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show BZW2 in A-431, U-251MG, U2OS, with annotated localisation: Plasma membrane (approved), Actin filaments (approved), Cytosol (approved) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host and isotype (caption: rabbit anti-BZW2 antibody); use BZW2 knockout material or a validated peptide-block condition as a biological specificity control. If using the caption’s SABC/DAB detection on breast sections, check endogenous peroxidase and biotin signal (caption: SABC/DAB).

⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A11832-1 paraffin-section caption does not state a fixative (caption: fixative not stated). The caption uses heat-mediated retrieval in EDTA at pH 8.0, but does not establish that retrieval is required; there is insufficient matched evidence to say frozen sections or IF are easier (caption: EDTA retrieval). For IF/ICC, compare staining with the reported cytosol, plasma membrane and actin-filament locations while checking autofluorescence in the chosen specimen (HPA subcellular: approved locations).

HPA tissue IHC evidence for BZW2

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — 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
Breast	Glandular cells	High	Protein (IHC)	HPA →
Gallbladder	Glandular cells	High	Protein (IHC)	HPA →
Testis	Leydig cells	High	Protein (IHC)	HPA →
Adrenal gland	Glandular cells	Medium	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Caudate	Glial cells	Not detected	Protein (IHC)	HPA →
Cerebellum	Cells in granular layer	Not detected	Protein (IHC)	HPA →
Epididymis	Glandular cells	Not detected	Protein (IHC)	HPA →
Hippocampus	Glial cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced BZW2 IHC Tips

Troubleshoot BZW2 chromogenic IHC by checking retrieval, compartment, cell type and controls before interpreting staining intensity.

How should I adjust retrieval when BZW2 staining is weak in paraffin sections?

Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A11832-1). The selected image used this retrieval before 10% goat-serum blocking and 2 μg/ml primary antibody overnight at 4°C (caption A11832-1). If signal is weak, compare modest changes to heating or cooling time on adjacent sections while keeping primary concentration and DAB development matched (standard IHC practice). Include a no-primary control and a positive reference containing glandular cells; seek stronger cytoplasmic signal without widespread background or tissue damage (standard IHC practice; UniProt: cytoplasm; HPA: high in breast glandular cells).

Could fixation explain a weak or patchy BZW2 IHC result?

The selected paraffin-section image does not state its fixative, so BZW2-specific fixation sensitivity is unknown (caption A11832-1). Record the fixative, fixation duration and processing history for each specimen, and compare similarly processed sections before attributing differences to BZW2 expression (standard IHC practice). A controlled fixation comparison can hold retrieval at EDTA pH 8.0 and primary concentration at 2 μg/ml while varying only the documented fixation condition (datasheet A11832-1; caption A11832-1; standard IHC practice). Check morphology and a no-primary control alongside staining, since damaged tissue and nonspecific signal can complicate interpretation (standard IHC practice).

Should BZW2 IHC appear cytoplasmic, membranous or nuclear?

Expect predominantly cytoplasmic staining in tissue sections, with intensity varying among tissues (UniProt: cytoplasm; HPA tissue IHC: cytoplasmic expression with varying intensity). Separate ICC/IF observations place BZW2 at the cytosol, plasma membrane and actin filaments, but those observations do not establish an identical pattern in paraffin IHC (HPA subcellular: approved locations). Because BZW2 has no transmembrane segment, interpret a membrane rim cautiously and check whether accompanying cytoplasmic signal is present (UniProt: topology and cytoplasm; standard IHC practice). Predominantly nuclear staining warrants review of retrieval, counterstain and no-primary controls before assignment to BZW2 (standard IHC practice).

Can epitope choice cause apparent differences between BZW2 IHC samples?

BZW2 has 2 annotated isoforms, but the supplied antibody evidence does not identify its immunogen or establish which isoforms it recognizes (UniProt: isoforms 1 and 2; caption A11832-1). The W2 domain spans residues 248–415, and annotated modifications include acetyllysine 117 and phosphoserines 412 and 414; none establishes the antibody’s epitope (UniProt: domains and modified residues). Keep retrieval at EDTA pH 8.0 while comparing matched sections and antibody lots, then document any reproducible staining differences (datasheet A11832-1; standard IHC practice). Do not assign an isoform or modification state from chromogenic staining alone without epitope mapping or an independent assay (standard IHC practice).

How should I assess BZW2 localisation in a separate multiplex IF experiment?

For a separate IF/ICC experiment, pair BZW2 with a validated marker for the expected cell population, such as glandular cells in a suitable tissue, and inspect each channel independently (HPA tissue IHC: high in breast and gallbladder glandular cells; standard IF practice). Choose fluorophores after measuring tissue autofluorescence; a spectrally separated far-red channel may improve contrast when shorter wavelengths are noisy (standard IF practice). Permeabilise when testing a cytosolic epitope, but establish the antibody’s epitope accessibility experimentally because its location is unspecified (UniProt: cytoplasm; HPA subcellular: cytosol; standard IF practice). Include single-stain and no-primary controls to assess bleed-through and background before interpreting overlap (standard IF practice).

How can I reduce diffuse brown staining without losing BZW2 signal?

The selected chromogenic image used a biotinylated secondary antibody, a streptavidin–biotin complex and DAB, so evaluate background within that detection workflow (caption A11832-1). Apply a peroxidase block and inspect no-primary and secondary-only controls to identify endogenous enzyme activity or secondary-dependent staining (standard IHC practice). If background persists, assess endogenous biotin where relevant, strengthen blocking or washing, and titrate the primary around the documented 2 μg/ml condition one variable at a time (caption A11832-1; standard IHC practice). Preserve interpretable cytoplasmic staining in expected cells while rejecting signal concentrated at folds, tissue edges or damaged areas (HPA tissue IHC: cytoplasmic profile; standard IHC practice).

What is a defensible way to score BZW2 chromogenic IHC? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and viable tissue region before scoring, then record the percentage of cytoplasmic-positive cells and staining intensity separately (HPA tissue IHC: cytoplasmic profile; standard IHC practice). An H-score combines percentages at intensity grades 0–3 into a 0–300 scale; use the same thresholds and DAB development conditions across sections (standard IHC practice). Normalize positive-cell counts to eligible cells, or positive area to viable tissue area in mm², rather than to the entire slide (standard IHC practice). Report glandular and other compartments separately where applicable, and exclude folds, necrosis and edge staining using preset rules (HPA tissue IHC: cell-specific staining levels; standard IHC practice).

How do I distinguish true BZW2 positivity from a staining artefact?

Give greatest weight to reproducible cytoplasmic signal in intact cells that exceeds no-primary background and follows the expected tissue pattern (UniProt: cytoplasm; HPA tissue IHC: varying cytoplasmic expression; standard IHC practice). High staining in breast or gallbladder glandular cells offers a reference, while normal appendix glandular cells were reported as not detected (HPA tissue IHC: listed cell levels). The catalog image shows staining in appendiceal adenocarcinoma, which should not be treated as evidence that normal appendix glandular cells are positive (caption A11832-1; HPA tissue IHC: appendix glandular cells not detected). Question isolated nuclear signal, edge staining, necrotic deposits or brown signal in enzyme-control sections before scoring them as BZW2 (standard IHC practice).

Boster reagents

Best BZW2 / eIF5-mimic protein 1 IHC Antibodies

A11832-1 has IHC images from human appendiceal and gastric adenocarcinoma, human placenta, and mouse colon paraffin sections; no IF images are provided (catalog: IHC and IF image captions).

Real IHC data

Anti-BZW2 Antibody ®

Cat # A11832-1

View product →

A11832-1 is listed for IHC and for human, mouse, and rat reactivity (catalog: applications and reactivity). Its IHC images show staining in human appendiceal adenocarcinoma, gastric adenocarcinoma, and placenta, and in mouse colon (catalog: IHC image captions).

Which to pick: Choose A11832-1 for chromogenic IHC on paraffin sections: its captions describe EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody, but do not report the fixative (A11832-1 IHC image captions). No listed SKU has an IF/ICC application or IF image (catalog: applications and IF images). For cross-species work, A11832-1 has human and mouse IHC images; rat reactivity is listed without a rat IHC image (catalog: reactivity and IHC image captions).

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

References

UniProt Consortium. UniProt entry Q9Y6E2 (5MP1_HUMAN, eIF5-mimic protein 1).
Human Protein Atlas. BZW2 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. BZW2 subcellular location (ICC-IF): Localized to the plasma membrane, cytosol and actin filaments..
Human Protein Atlas. BZW2 antibody validation summary (2 antibodies).
Expression, oncological and immunological characterizations of BZW1/2 in pancreatic adenocarcinoma. Frontiers in genetics 2022 — PMC9576853.
BZW2 promotes malignant progression in lung adenocarcinoma through enhancing the ubiquitination and degradation of GSK3β. Cell death discovery 2024 — PMC10904796.
BZW2/5MP1 acts as a promising target in hepatocellular carcinoma. Journal of Cancer 2021 — PMC8317536.
Polyamine metabolism patterns characterized tumor microenvironment, prognosis, and response to immunotherapy in colorectal cancer. Cancer cell international 2023 — PMC10197465.
PubMed PMID:11042152 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:12690205 — UniProt-cited evidence.