BAG6 / Large proline-rich protein BAG6 · IHC design guide

Design Immunohistochemistry for BAG6

Plan BAG6 chromogenic IHC in paraffin sections using the cytoplasmic and nuclear tissue pattern, with strong testis staining as a reference (HPA tissue IHC). The catalog antibody's IHC dilution is 2–5 μg/mL (datasheet A00967-1).

Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
Immunohistochemistry protocol sheet for BAG6 (IHC for BAG6): expected localisation Cytoplasmic and nuclear staining (HPA tissue IHC), antibody A00967-1, validated IHC image, and IHC protocol steps
Printable BAG6 IHC protocol sheet — expected localisation Cytoplasmic and nuclear staining (HPA tissue IHC), antibody A00967-1, controls and protocol steps. Open the full BAG6 IHC guide →

BAG6 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 nuclear staining (HPA tissue IHC)
Staining pattern Cytoplasmic/nuclear in most tissues; abundant in testis (HPA tissue IHC)
Antigen retrieval EDTA pH 8.0 HIER, heat-mediated (datasheet A00967-1)
Positive control ⓘ Lung+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 across sections. (standard IHC practice; not target-specific)
Caveat Tumor and myeloid cells can release BAG6 in exosomes (UniProt)
Regulation No staining-intensity regulator established (UniProt)
Isoform / epitope 5 isoforms; epitope coverage is unspecified (UniProt)
Section 1

Recommended BAG6 IHC & IF Protocols

The catalog antibody protocol (datasheet: A00967-1) and two published BAG6 IHC protocols (PMC6052567; PMC8748226) provide starting points for paraffin sections.

Recommended immunohistochemistry (IHC-P) protocol parameters
SampleParaffin-embedded human lung cancer tissue; fixative not specified (datasheet A00967-1)
FixationImage fixative and duration unreported (datasheet A00967-1); verify before use.
Sectioning4–5 µm sections on charged slides (standard)
DeparaffinisationXylene, graded ethanol series to water (standard)
Antigen retrievalHeat retrieval: EDTA pH 8.0 (datasheet A00967-1); 20 min, 95–100 °C (standard)
Peroxidase block3% H2O2, 10 min, room temperature (standard)
Blocking10% goat serum (datasheet A00967-1)
Primary antibodyRabbit anti-BAG6, 2-5μg/ml (datasheet A00967-1)
Primary incubationOvernight at 4 °C (datasheet A00967-1)
DetectionHRP-conjugated secondary, DAB chromogen (datasheet A00967-1)
CounterstainHematoxylin, blue, dehydrate and mount (standard)
Expected resultBAG6-positive staining in alveolar cells type II of lung (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and nuclear expression in most tissues, highly abundant in testis. No signal in the no-primary control.
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet: A00967-1), then optimize the primary dilution for your sample.
Section 2

What Is the Expected BAG6 Staining Pattern?

BAG6 is normally found in the cytosol and nucleus and has no transmembrane segment (UniProt P46379). In paraffin-section IHC, expect cytoplasmic and nuclear staining across many tissues, with particularly abundant staining in testis (HPA tissue IHC: Enhanced reliability). High-staining examples are spermatogonia, lung alveolar type II cells and placental cytotrophoblasts (HPA tissue IHC: High in each cell type).

What am I looking at on my slide?
Nuclear and cytoplasmic staining in the expected cells, with strong spermatogonial signal.This fits BAG6’s reported compartments (UniProt P46379: cytosol and nucleus) and the tissue pattern (HPA tissue IHC: cytoplasmic and nuclear expression in most tissues; highly abundant in testis). Judge intensity within the relevant cell population, since other tissues and cell types have different reported levels (HPA tissue IHC: High, Medium and Low categories).
Signal appears confined to an unexpected compartment, such as a sharp cell-surface rim.A membrane-rim pattern alone does not match the reported intracellular pattern (UniProt P46379: cytosol and nucleus; no transmembrane segment). Consider nonspecific staining or a detection artefact before assigning it to BAG6. Extracellular release in exosomes is reported, but it does not establish a diagnostic membrane-rim IHC pattern (UniProt P46379: extracellular exosomes).
A cell population stains strongly where the HPA profile reports low staining.For example, strong signal in skeletal myocytes or adipocytes conflicts with their reported low staining (HPA tissue IHC: Low in skeletal muscle myocytes and adipose tissue adipocytes). Check cell identification and controls; cross-reactivity or endogenous detection activity may explain the result (standard IHC practice). An HPA Low designation does not mean every cell must be blank.
Color spreads across tissue structures and obscures cell boundaries.Diffuse background prevents a reliable nuclear-versus-cytoplasmic call (UniProt P46379: nucleus and cytosol; HPA tissue IHC: cytoplasmic and nuclear pattern). It can reflect nonspecific antibody binding or detection background (standard IHC practice). Interpret the slide only after comparison with an appropriate detection control and a defined cell-level pattern.
Expected cells lack visible signal in a putative positive section.Absence of staining in testis spermatogonia, lung alveolar type II cells or placental cytotrophoblasts is inconsistent with their reported High levels (HPA tissue IHC: High in each). First verify that the named cells are present and identifiable. A failed stain remains possible; a negative-looking field without those cells cannot assess the expected positive pattern (standard IHC practice).
💡Expected BAG6 appearanceA convincing positive shows nuclear and cytoplasmic staining in identifiable BAG6-expressing cells, especially strong staining in spermatogonia (HPA tissue IHC: High in spermatogonia; cytoplasmic and nuclear profile); isolated membrane-rim color or featureless background warrants an artefact check (UniProt P46379: no transmembrane segment; standard IHC practice).
How each factor affects the staining
Tissue and cell selectionThe HPA profile has low tissue specificity, yet individual cell levels vary (HPA tissue IHC: Low tissue specificity; High, Medium and Low cell categories). A section containing High-staining cells makes an interpretable positive reference; Low-staining cells alone are a weak failure check (HPA tissue IHC: named High and Low cells).
Antibody validationThe tissue profile has Enhanced reliability, meaning high consistency between antibody staining and RNA expression data (HPA tissue IHC: Enhanced). Individual antibodies have separate IHC statuses: HPA045116 and HPA053291 are Enhanced; CAB020704 is Supported (HPA antibody validation). These labels support interpretation but do not guarantee every staining run.
Isoforms and epitopeFive BAG6 isoforms are listed, but the supplied record does not map an IHC antibody epitope to them (UniProt P46379: isoforms 1–5). If stains disagree, epitope coverage is a question to resolve from the antibody’s documentation; the isoform count alone cannot predict which cells or compartments an antibody will reveal.
Topology and extracellular releaseBAG6 has no transmembrane segment and no signal peptide or propeptide (UniProt P46379). Release in exosomes from tumor and myeloid dendritic cells is reported (UniProt P46379: extracellular exosomes). These facts do not justify treating a surface-only chromogenic pattern as the expected tissue result.
IF/ICC Q&A: Where should signal appear?Mainly in the nucleoplasm, with additional vesicular and cytosolic localization (HPA subcellular ICC-IF: nucleoplasm Supported; vesicles Approved; cytosol Supported). This is evidence from ICC-IF images; use the tissue IHC profile to judge paraffin-section staining (HPA tissue IHC: cytoplasmic and nuclear expression).
Detection backgroundEndogenous enzyme activity and nonspecific antibody binding can add color in chromogenic IHC (standard IHC practice). They are possible explanations for background, not documented BAG6-specific properties; assess them with suitable detection controls before changing a biological interpretation.
Why is my staining missing, weak or wrong?
SituationLikely causeNext action
No staining in a positive reference sectionThe expected cells may be absent from the examined field, or the IHC workflow may have failed (HPA tissue IHC: High in spermatogonia, alveolar type II cells and cytotrophoblasts; standard IHC practice).Confirm cell identity and section quality, then review retrieval, antibody use and detection against the IHC-validated antibody’s instructions (standard IHC practice). Do not infer a BAG6-specific retrieval requirement from the HPA tissue profile.
Only a membrane-like rim stainsA surface-only pattern conflicts with the reported nuclear and cytosolic localization and lack of a transmembrane segment (UniProt P46379).Check a detection control and inspect whether the same rim appears in unrelated cells (standard IHC practice). Seek reproducible nuclear or cytoplasmic signal in HPA High cells before calling the rim BAG6 (HPA tissue IHC: High cell examples).
Unexpected cell types stain more strongly than expected cellsCell misidentification, cross-reactivity or endogenous detection activity can mislead interpretation (standard IHC practice); HPA reports different staining levels by cell type (HPA tissue IHC: High, Medium and Low categories).Recheck morphology and compare named High and Low cell populations on suitable sections (HPA tissue IHC: cell-level categories). Use an appropriate detection control to examine nonspecific color (standard IHC practice).
Diffuse color masks nuclei and cytoplasmNonspecific binding or detection background can obscure the reported cellular distribution (standard IHC practice; HPA tissue IHC: cytoplasmic and nuclear profile).Review blocking, antibody concentration, washes and chromogen development using the validated IHC workflow (standard IHC practice). Reassess localization only when cell boundaries and the counterstain are readable.
A Low-staining tissue looks negativeLow is a relative HPA staining category, not a guaranteed negative control (HPA tissue IHC: Low in oral mucosa squamous cells, skeletal myocytes and other listed cells).Compare the run with a section containing an HPA High cell population, such as testis spermatogonia (HPA tissue IHC: High in spermatogonia). Interpret the Low tissue only in that context.
IF/ICC looks more nuclear than tissue IHCICC-IF reports a main nucleoplasmic location, while tissue IHC reports both cytoplasmic and nuclear expression (HPA subcellular ICC-IF; HPA tissue IHC).Score each application against its own reported pattern and antibody validation status (HPA subcellular ICC-IF; HPA antibody validation). Do not use an ICC-IF image alone to reject an otherwise consistent paraffin-section IHC result.

Sample controls for BAG6 IHC & IF

🧪Run lung first and look for staining in alveolar type II cells (HPA: High in lung alveolar type II cells). HPA detects BAG6 in all 45 scored tissues, so there is no validated negative tissue; use no-primary and isotype controls, and treat unstained cells within the lung section as background comparators rather than confirmed BAG6-negative cells (HPA: no negative tissue rows; detected in all 45 scored tissues).
Positive control tissue: Lung (Alveolar cells type II, HPA High)
Negative control tissue: None in HPA: BAG6 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 BAG6 in A-431, U-251MG, U2OS, RPTEC/TERT1, hTERT-RPE1 (serum starved), NIH 3T3, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Run a no-primary, secondary-only slide and a host- and concentration-matched rabbit IgG isotype control alongside a BAG6 knockout control where available (selected-SKU caption: rabbit primary; standard IHC specificity controls). Block endogenous peroxidase and check for native pigment in lung before interpreting DAB staining (selected-SKU caption: lung tissue and HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact selected-SKU paraffin-section caption does not state a fixative (selected-SKU caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 was used for the reported paraffin IHC image, but retrieval dependence is unreported (selected-SKU caption: heat-mediated EDTA retrieval). Frozen-section and tissue IF feasibility cannot be established from the supplied evidence; HPA reports ICC-IF images and nucleoplasmic localisation, while lung autofluorescence may complicate IF interpretation (HPA: ICC-IF cell-line images and supported nucleoplasmic localisation; standard IF practice).

HPA tissue IHC evidence for BAG6

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

TissueCell typeLevelEvidenceSource
Lung Alveolar cells type II High Protein (IHC) HPA →
Placenta Cytotrophoblasts High Protein (IHC) HPA →
Testis Spermatogonia cells High Protein (IHC) HPA →
Adrenal gland Glandular cells Medium Protein (IHC) HPA →
Appendix Glandular cells Medium Protein (IHC) HPA →

Undetected expression · recommended negative controls

TissueCell typeLevelEvidenceSource
None in HPA: BAG6 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
Section 3

Advanced BAG6 IHC Tips

Use the documented paraffin-section staining conditions as a starting point, then assess BAG6 signal by compartment, cell type and matched controls.

What retrieval should I try first when BAG6 staining is weak in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 (datasheet A00967-1). The selected paraffin-section example used that retrieval before 2 μg/ml primary antibody overnight at 4°C, so check retrieval alongside antibody incubation rather than changing both at once (caption A00967-1). Compare adjacent sections with and without retrieval, using the same detection and imaging settings, to distinguish weak epitope exposure from weak chromogen development (standard IHC practice). Score nuclear and cytoplasmic staining separately because both are plausible BAG6 locations, and excessive diffuse signal can obscure that distinction (HPA tissue IHC; UniProt P46379 subcellular location).
Could fixation explain inconsistent BAG6 staining across paraffin blocks?
Yes, fixation can alter epitope accessibility in paraffin IHC, but BAG6-specific fixation sensitivity is unknown from the supplied evidence (standard IHC practice; caption A00967-1: fixative unreported). Record each block’s fixative and processing history, and compare matched sections under the same EDTA pH 8.0 retrieval and primary-antibody conditions (datasheet A00967-1; standard IHC practice). Use a consistently stained control section in each run to help separate block-to-block variation from staining-run variation (standard IHC practice). Do not infer fixation tolerance from BAG6’s nuclear and cytoplasmic tissue pattern or its lack of a transmembrane segment; neither establishes how this antibody’s epitope survives processing (HPA tissue IHC; UniProt P46379 topology).
Should BAG6 stain nuclei, cytoplasm, or both in tissue sections?
Expect potentially both nuclear and cytoplasmic staining in paraffin sections, since the tissue profile reports both in most tissues (HPA tissue IHC). The subcellular record places BAG6 in cytosol and nucleus, while the cell imaging summary identifies nucleoplasm as its main location with additional cytosol and vesicles (UniProt P46379 subcellular location; HPA subcellular). Assess compartments independently against a hematoxylin counterstain, and compare cells within the same section before calling a diffuse deposit positive (standard IHC practice). An apparent membrane-only rim needs scrutiny because BAG6 has no transmembrane segment; cytosolic retention can involve GET4 (UniProt P46379 topology and interactions).
How can epitope choice affect detection of BAG6 isoforms?
BAG6 has 5 listed isoforms, so antibody reactivity across them depends on the epitope recognized by the catalog antibody (UniProt P46379 isoforms; standard immunostaining principle). The supplied caption documents paraffin-section staining with A00967-1 but does not map its epitope or establish isoform coverage (caption A00967-1). Ask for an epitope map or assess independently validated reagents before interpreting different staining patterns as isoform-specific, and keep retrieval and detection conditions comparable (standard IHC practice). BAG6 contains an N-terminal ubiquitin-like domain at residues 17–92 and reported modified residues, but those features alone cannot identify which epitope this antibody detects (UniProt P46379 domains and modified residues).
How should I assess BAG6 by IF alongside a cell-type marker?
For IF on sections, pair BAG6 with a marker independently validated for the expected cell type, and check whether the two signals occupy the same cells rather than merely overlapping tissue areas (standard IF practice). Type II alveolar cells in lung are a documented high-expression reference, but that tissue profile does not validate a particular multiplex marker or IF staining condition (HPA tissue IHC). Choose spectrally separated fluorophores and inspect unstained tissue for autofluorescence before assigning a faint BAG6 signal (standard IF practice). Permeabilise sufficiently for access to nuclear and cytosolic epitopes, then compare with a gentler condition if compartment boundaries disappear; the antibody’s precise epitope is not supplied (UniProt P46379 subcellular location; caption A00967-1; standard IF practice).
How do I reduce diffuse or granular background in BAG6 chromogenic IHC?
First inspect a no-primary control, tissue edges and damaged areas under the same DAB development conditions to identify deposits unrelated to primary-antibody binding (standard IHC practice). The selected paraffin-section example used 10% goat serum blocking, 2 μg/ml primary antibody and an HRP/DAB detection system; these are documented conditions to reproduce before adjusting signal strength (caption A00967-1). Apply a peroxidase block and compare shorter DAB development or a primary-antibody titration when background remains high (standard IHC practice). Keep nuclear and cytoplasmic signal distinct during review, since BAG6 can occur in both compartments and a uniform haze can falsely inflate positivity (HPA tissue IHC; standard IHC practice).
What is a defensible way to score BAG6 staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the analysis region and cell population before scoring, then report the percentage of positive cells and an intensity-weighted H-score separately for nuclear and cytoplasmic staining (standard IHC practice; HPA tissue IHC). Use the same positivity threshold, DAB development conditions and imaging settings across comparison groups, with blinded review where feasible (standard IHC practice). Normalise positive-cell counts to the number of eligible cells, or use positive-cell density per mm² of viable analysed tissue when cell counting is impractical (standard IHC practice). Record excluded necrotic and edge regions so variable tissue quality does not masquerade as a BAG6 difference (standard IHC practice).
How can I distinguish true BAG6 staining from tissue artefact?
A credible result should show cellular nuclear and/or cytoplasmic signal consistent with BAG6’s reported distribution, with the relevant cells identifiable on the counterstain (HPA tissue IHC; UniProt P46379 subcellular location; standard IHC practice). High staining in documented type II alveolar cells, cytotrophoblasts or spermatogonia can provide context, but those references do not make every stained cell in another specimen a confirmed positive (HPA tissue IHC). Treat staining confined to section edges, necrotic material or a no-primary control as possible artefact, including endogenous peroxidase activity in an HRP/DAB assay (standard IHC practice). Scrutinise an isolated membrane-only pattern because BAG6 has no transmembrane segment, while avoiding a claim that every extracellular deposit is false (UniProt P46379 topology and subcellular location).
Boster reagents

Best BAG6 / Large proline-rich protein BAG6 IHC Antibodies

A00967-1 has pictured human paraffin-section IHC and PC3 cell IF data (catalog image captions); A00967-1 and M00967 list human, mouse, and rat reactivity (catalog reactivity fields).

Real IHC data IHC analysis of BAT3/BAG6 using anti-BAT3/BAG6 antibody (A00967-1). BAT3/BAG6 was detected in a paraffin-embedded section of human lung cancer 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-BAT3/BAG6 Antibody (A00967-1) overnight at 4°C. Peroxidase Conjugated Goat Anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Rabbit IgG Super Vision Assay Kit (Catalog # SV0002) with DAB as the chromogen.
Anti-BAT3/BAG6 Antibody ®
Cat # A00967-1

The A00967-1 card renders with IHC data from a human lung cancer paraffin section (card image caption). Its catalog also documents IHC in human ovarian serous adenocarcinoma paraffin sections and IF in PC3 cells (catalog image captions).

Which to pick: For tissue IHC, choose A00967-1: its own human paraffin-section captions document EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody; the fixative is unreported (catalog IHC image captions). For IF/ICC, A00967-1 has pictured PC3 cell IF at 5 μg/ml, while M00967 lists IF/ICC without a supplied image (catalog IF caption; M00967 application and image fields). For mouse or rat samples, both SKUs list reactivity, but the supplied IHC/IF images support human samples only; M00967 is a rabbit monoclonal, clone 25B57 (catalog reactivity, image and clone fields).

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

References

  1. UniProt Consortium. UniProt entry P46379 (BAG6_HUMAN, Large proline-rich protein BAG6).
  2. Human Protein Atlas. BAG6 tissue IHC expression (reliability: Enhanced).
  3. Human Protein Atlas. BAG6 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to vesicles and cytosol..
  4. Human Protein Atlas. BAG6 antibody validation summary (3 antibodies).
  5. The dynamic changes in the number of uterine natural killer cells are specific to the eutopic but not to the ectopic endometrium in women and in a baboon model of endometriosis. Reproductive biology and endocrinology : RB&E 2018 — PMC6052567.
  6. Nodular lymphocyte predominant hodgkin lymphoma and T cell/histiocyte rich large B cell lymphoma--endpoints of a spectrum of one disease?. PloS one 2013 — PMC3823948.
  7. GET4 is a novel driver gene in colorectal cancer that regulates the localization of BAG6, a nucleocytoplasmic shuttling protein. Cancer science 2022 — PMC8748226.
  8. SGTA associates with intracellular aggregates in neurodegenerative diseases. Molecular brain 2021 — PMC7986274.
  9. PubMed PMID:2156268 — UniProt-cited evidence.
  10. PubMed PMID:17974005 — UniProt-cited evidence.
  11. PubMed PMID:14702039 — UniProt-cited evidence.