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AQP6 / Aquaporin-6 · IHC design guide
Design Immunohistochemistry for AQP6
Plan chromogenic IHC-P for AQP6 with distal renal tubules as a positive control and cytoplasmic staining as the expected pattern (HPA tissue IHC). Score staining with attention to presumed off-target binding (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
AQP6 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 | Renal tubular cytoplasm (HPA tissue IHC); vesicle membrane (UniProt) | |
| Staining pattern | High cytoplasmic staining in distal renal tubules (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Kidney | |
| 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). Selected-image fixative and duration unreported (datasheet PA2092); verify before use. | |
| Caveat | Presumed off-target staining may confound scoring (HPA tissue IHC) | |
| Regulation | No expression regulator annotated (UniProt) | |
| Isoform / epitope | No annotated isoforms; epitope side affects access (UniProt) |
Section 1
Recommended AQP6 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is paired with published paraffin-section procedures for mouse cochlea (PMC2810475) and human ovary (PMC12399404).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet PA2092); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in citrate buffer, pH 6.0, 20 min at 95–98 °C (standard rule: cytoplasmic / membrane antigen) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-AQP6, 0.5-1μg/ml (datasheet PA2092) |
| 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 | AQP6-positive staining in distal tubules of kidney (HPA tissue IHC: High). HPA tissue profile: Selective cytoplasmic expression in renal tubules. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 heat retrieval at 95–98 °C for 20 min (page retrieval rule); the ovarian article does not specify retrieval conditions (PMC12399404).
Section 2
What Is the Expected AQP6 Staining Pattern?
In paraffin-section IHC, expect selective cytoplasmic staining in renal tubules, with high staining reported in distal tubules (HPA: tissue IHC, Enhanced). AQP6 is assigned to the cytoplasmic vesicle membrane and has six transmembrane segments (UniProt Q13520: subcellular location and topology). HPA rates its tissue IHC reliability Enhanced, while noting medium consistency with RNA data and presumed off-target staining that was disregarded (HPA: reliability description).
| Strong cytoplasmic signal in distal renal tubules, with surrounding tissue comparatively quiet. | This matches HPA's selective cytoplasmic renal-tubule profile and High distal-tubule staining (HPA: tissue IHC). Score the tubular cells and their compartment together; intensity alone cannot establish specificity. A vesicle-associated cytoplasmic appearance is consistent with AQP6's assigned location (UniProt Q13520: subcellular location). |
| Predominantly nuclear staining or broad staining outside the expected cytoplasmic compartment. | Treat this as a localization mismatch requiring investigation, since the supported IHC pattern is cytoplasmic and UniProt places AQP6 at cytoplasmic vesicle membranes (HPA: tissue IHC; UniProt Q13520: subcellular location). Review morphology and controls before assigning the signal to AQP6. |
| Clear staining in cells reported as negative, such as adipocytes or adrenal glandular cells. | The result conflicts with those HPA tissue observations (HPA: Not detected in adipocytes and adrenal glandular cells). Consider nonspecific antibody binding or endogenous chromogenic detection activity as general IHC possibilities. HPA also reports presumed off-target staining that it disregarded (HPA: reliability description). |
| Diffuse chromogen across many structures, including areas without the expected tubular pattern. | This is insufficient evidence for AQP6 positivity: the reported tissue pattern is selective rather than diffuse (HPA: tissue IHC). In general IHC practice, assess background against a matched negative detection control, then review blocking, antibody concentration, washes, and detection conditions. |
| No staining in a kidney section with identifiable distal tubules. | This misses the supplied known-positive pattern (HPA: High in distal tubules). Check tissue preservation, section quality, primary-antibody application, retrieval and detection performance using appropriate controls as general IHC practice. Do not conclude that AQP6 is absent from the sample solely from a failed staining run. |
💡Expected AQP6 appearanceCall a result consistent with AQP6 when staining is strong and selective in the cytoplasm of distal renal tubules (HPA: High in distal tubules; selective cytoplasmic expression), while treating widespread nuclear or unrelated-cell staining as a specificity concern (UniProt Q13520: cytoplasmic vesicle membrane; HPA: presumed off-target staining disregarded).
| Cell and tissue distribution | Kidney distal tubules provide the positive reference (HPA: High in distal tubules). HPA reports Not detected in several sampled cell types, including adipocytes and adrenal glandular cells (HPA: tissue IHC); use those observations as comparisons for the sampled cells, not as a claim that every cell in those organs is negative. |
| Compartment and topology | AQP6 is a six-pass protein assigned to the cytoplasmic vesicle membrane (UniProt Q13520: topology and subcellular location). Interpret a cytoplasmic tubular pattern in light of that assignment and HPA's tissue IHC observation (HPA: selective cytoplasmic renal-tubule expression). The record does not define a more precise chromogenic vesicle pattern. |
| Strength of the IHC evidence | HPA labels the tissue IHC result Enhanced and lists antibody HPA015278 as IHC Enhanced (HPA: reliability; HPA: antibody validation). Its description also notes medium staining-to-RNA consistency and presumed off-target binding that was disregarded (HPA: reliability description). Retain morphology and controls when judging unexpected positives. |
| IF/ICC Q: Does the HPA membrane summary establish an image-validated IF pattern? | A: HPA summarizes the subcellular location as Membrane, but gives no main location or cell lines with ICC-IF images (HPA: subcellular record). That summary supplies no cell-image pattern to score here; use the separate IF/ICC guide for that application. |
| Retrieval and epitope access | The supplied records give AQP6 topology but no antibody epitope or target-specific fixation sensitivity (UniProt Q13520: topology; HPA: supplied tissue IHC record). If optimizing paraffin-section retrieval, compare controlled conditions as general IHC practice; do not attribute a signal change to a documented AQP6 fixation effect. |
| Situation | Likely cause | Next action |
|---|---|---|
| Distal tubules stain weakly or not at all. | The run has not reproduced the reported positive pattern (HPA: High in distal tubules); the supplied records do not identify which preparation step failed. | Repeat with a suitable kidney positive control and verify tissue morphology, primary-antibody application, retrieval and detection as general IHC practice. Compare changes one at a time before interpreting a negative specimen. |
| Signal is mainly nuclear. | That compartment conflicts with cytoplasmic renal-tubule staining and the assigned cytoplasmic vesicle membrane location (HPA: tissue IHC; UniProt Q13520: subcellular location). | Recheck the counterstain and cellular boundaries, then compare a negative detection control and a known-positive kidney section as general IHC practice. Withhold an AQP6-positive call for the nuclear signal. |
| Adipocytes or adrenal glandular cells stain clearly. | Those sampled cell types are reported Not detected (HPA: tissue IHC); nonspecific binding or endogenous detection activity are general IHC possibilities. | Check a control that omits the primary antibody and review blocking and detection conditions as general IHC practice. Interpret any remaining signal cautiously because presumed off-target staining was disregarded in HPA's assessment (HPA: reliability description). |
| Chromogen appears diffusely across the section. | The distribution lacks the reported selective renal-tubule pattern (HPA: tissue IHC); excess background is a general IHC possibility. | Compare the negative detection control, review washing and blocking, and titrate the primary antibody within its documented IHC instructions as general IHC practice. Reassess specificity only after the diffuse signal is controlled. |
| Signal appears at a crisp cell surface without a convincing tubular cytoplasmic pattern. | UniProt assigns AQP6 to cytoplasmic vesicle membranes, while HPA reports cytoplasmic renal-tubule staining (UniProt Q13520: subcellular location; HPA: tissue IHC). | Inspect the cellular boundaries and tubular morphology, then compare the kidney positive control. Treat the surface-only appearance as unresolved; the supplied evidence does not define it as the expected paraffin-section pattern. |
| An IF/ICC image seems to show a different compartment. | HPA provides a Membrane summary but no main location or ICC-IF cell images for AQP6 (HPA: subcellular record). | Evaluate the image with IF/ICC-specific controls in its own guide. Do not use the HPA summary as image-level confirmation or transfer the paraffin-section IHC scoring call directly to IF/ICC. |
Experiment evidence
IHC & IF images showing AQP6 staining
PA2092 · IHCAnti-Aquaporin 6 antibody, PA2092, IHC(P) IHC(P): Human Placenta Tissue
PA2092 · IHCAnti-Aquaporin 6 antibody, PA2092, IHC(P) IHC(P): Human Lung Cancer Tissue
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000086159-AQP6/tissue/cerebral+cortex#imid_17534095
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000086159-AQP6/tissue/colon#imid_17534013
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000086159-AQP6/tissue/liver#imid_17534022
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000086159-AQP6/tissue/kidney#imid_17534023
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for AQP6 IHC & IF
🧪Run kidney first and look for AQP6 staining in distal tubules (HPA: High in kidney distal tubules). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); on the kidney slide, assess cells outside stained distal tubules for background, without assuming a particular cell type is AQP6-negative (HPA: High in distal tubules only).
Positive control tissue: Kidney (Distal tubules, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for AQP6; derive a cell-line control from the positive tissue's cell type (Distal tubules) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and a host-matched isotype control for a monoclonal primary, or matched nonimmune IgG for a polyclonal primary; use AQP6 knockout tissue as a biological negative if available (standard IHC practice). Quench endogenous peroxidase and, if using biotin-based detection, block endogenous biotin to check for kidney background (standard chromogenic IHC practice).
⚠️Feasibility: A target-specific fixation window and the effect of fixation on AQP6 staining are unreported in the supplied evidence; the selected PA2092 paraffin-section caption also leaves the fixative unreported (PA2092 IHC(P) caption). Antigen-retrieval dependence is unreported, so compare retrieval conditions on matched paraffin sections (standard IHC practice). The supplied evidence does not establish that frozen sections or IF are easier; for kidney IHC, endogenous biotin can produce background with biotin-based detection (standard IHC practice).
HPA tissue IHC evidence for AQP6
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Presumed off target binding observed and disregarded.). 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 |
|---|---|---|---|---|
| Kidney | Distal tubules | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced AQP6 IHC Tips
Troubleshooting chromogenic AQP6 IHC in paraffin sections, with a focused IF comparison.
What retrieval conditions should I start with for AQP6 IHC in paraffin sections?
Start with citrate buffer at pH 6.0 for heat induced retrieval at 95–98 °C for 20 min (page retrieval rule). Let sections cool in buffer, then compare matched sections with identical antibody incubation and chromogen development so retrieval is the tested variable (standard IHC practice). AQP6 has 6 transmembrane segments and a cytoplasmic C terminus at residues 235–282, but the antibody epitope is unspecified here (UniProt Q13520 topology; supplied antibody evidence). Judge retrieval by selective distal tubular staining alongside intact tissue morphology (HPA: high in kidney distal tubules; standard IHC practice). If signal is weak, optimize heating time on replicate sections before changing buffer chemistry (standard IHC practice).
How should I troubleshoot weak staining when fixation history varies between blocks?
Target specific fixation sensitivity is unknown; neither the supplied caption nor the protein record establishes how fixation changes AQP6 staining (selected PA2092 caption; UniProt Q13520 record). The selected PA2092 image identifies human placenta IHC(P), but its caption does not report a fixative (selected PA2092 caption). Record each block’s fixative and fixation duration where available, then compare sections under the same pH 6.0, 20 min retrieval and detection conditions (page retrieval rule; standard IHC practice). Include a kidney reference with distal tubules when available, since that compartment has high reported staining (HPA: kidney distal tubules, High). Treat any block dependent difference as an observation requiring replication, rather than evidence of an AQP6 specific fixation effect (standard IHC practice).
Should AQP6 staining appear on the cell surface or within distal tubular cells?
Expect a selective intracellular, cytoplasmic pattern in renal distal tubules when interpreting paraffin section IHC (HPA: selective cytoplasmic expression; kidney distal tubules, High). AQP6 is assigned to cytoplasmic vesicle membranes, so punctate or granular cytoplasmic signal is biologically plausible (UniProt Q13520: cytoplasmic vesicle membrane). Evaluate signal within identifiable tubule cells, checking that the chromogen follows cellular boundaries and recurs across comparable tubules (standard IHC practice). Uniform nuclear staining or staining restricted to tissue edges does not fit the reported compartment and warrants a control review (UniProt Q13520 localisation; standard IHC practice). The HPA subcellular summary says “Membrane” without an available main location or ICC/IF images, so it does not establish a cell surface IHC pattern (HPA subcellular payload).
How does the unknown antibody epitope affect interpretation of my AQP6 staining?
The record lists a single 282 amino acid AQP6 chain and 0 annotated isoforms, so this payload offers no isoform specific staining interpretation (UniProt Q13520 processing; isoforms). Its 6 transmembrane segments separate cytoplasmic and extracellular regions, including a cytoplasmic C terminus at residues 235–282 (UniProt Q13520 topology). The supplied evidence does not identify the catalog antibody’s epitope, so do not assume which membrane face retrieval exposes or which sequence the reagent recognizes (supplied antibody evidence). Compare staining with a verified antibody epitope map or an orthogonal assay if those become available (standard IHC validation practice). Report signal as antibody dependent until specificity controls support attribution to AQP6 (standard IHC practice).
How can IF help assess the AQP6 pattern seen by chromogenic IHC?
On the separate IF/ICC guide page, multiplex AQP6 with a validated distal tubular marker to test whether signal occupies the expected cells (HPA: kidney distal tubules, High; standard IF practice). Choose a spectrally separated, preferably far red fluorophore after examining unstained tissue for autofluorescence, and acquire each channel separately before merging (standard IF practice). If a mapped epitope is cytoplasmic, trial mild permeabilisation, such as 0.1% detergent for 5 min, against an otherwise matched condition; do not assume an epitope location from topology alone (UniProt Q13520 topology; standard IF practice). The supplied record has no ICC/IF images or direct fixation evidence, so establish IF fixation and antibody performance experimentally (HPA subcellular payload; supplied evidence). Compare any intracellular IF pattern with the selective cytoplasmic renal staining reported for tissue IHC (HPA tissue IHC).
What controls help separate AQP6 staining from chromogenic background?
Run a no primary control through the same detection sequence and inspect the chromogen before assigning faint staining to AQP6 (standard IHC practice). For peroxidase based detection, include an endogenous peroxidase block, for example 3% hydrogen peroxide for 10 min, and keep DAB development matched across sections (standard chromogenic IHC practice). Review nonspecific secondary binding with a suitable blocking step and the detection system’s control tissue (standard IHC practice). AQP6 staining should preferentially involve renal distal tubules, while several surveyed nonrenal cell types were not detected in the HPA panel (HPA tissue IHC). Broad staining across unrelated compartments deserves extra scrutiny because HPA reports presumed off target binding in its tissue survey (HPA reliability description).
How should I score AQP6 IHC across kidney sections without losing compartment specificity? ⚠ ANSWER MARKED FOR VERIFICATION
Define distal tubules on morphology before scoring, because HPA reports high AQP6 staining in that renal compartment (HPA: kidney distal tubules, High). Record the percentage of positive distal tubular cells and intensity on a consistent 0–3 scale, then calculate an H score from 0–300 if intensity varies (standard IHC scoring practice). Normalize counts to the number of evaluable distal tubular cells, or stained area to evaluable distal tubular area, rather than total section area (standard IHC quantification practice). Use matched section thickness, retrieval, and DAB development for comparisons, and exclude folds, necrosis, and edge staining by predefined criteria (standard IHC practice). Keep other renal compartments separate because the reported tissue profile is selective (HPA tissue IHC).
When should apparent AQP6 positivity be treated as artefact?
Give greatest weight to reproducible cytoplasmic signal in recognizable renal distal tubular cells (HPA: selective cytoplasmic expression; kidney distal tubules, High). Nuclear only staining, uniform signal in unrelated cell populations, or staining concentrated at cut edges conflicts with that pattern and needs control review (HPA tissue IHC; standard IHC practice). Exclude necrotic regions and compare suspicious deposits with a no primary section and the endogenous peroxidase blocked section before scoring DAB signal (standard chromogenic IHC practice). Interpret the PA2092 human placenta IHC(P) image cautiously: its caption does not state the fixative or establish a renal localisation pattern (selected PA2092 caption). HPA describes medium staining to RNA consistency and presumed off target binding, so morphology and controls remain essential to a positive call (HPA reliability description).
Boster reagents
Best AQP6 / Aquaporin-6 IHC Antibodies
PA2092 has human paraffin-section IHC images from placenta and lung cancer tissue (catalog: PA2092 image captions); neither listed antibody has IF/ICC data (catalog: application lists and image captions).
Real IHC data
Anti-Aquaporin 6/AQP6 Antibody ®
Cat # PA2092
PA2092 will render with its human placenta IHC figure (card: PA2092 figure tag and caption). Its catalog also lists a human lung cancer IHC image; IHC is an application and Human is the listed reactivity (catalog: PA2092 image captions, applications and reactivity).
Which to pick: Choose PA2092 for human paraffin-section IHC because its own captions show human placenta and lung cancer IHC(P) images; the fixative is unreported (catalog: PA2092 image captions). A10607 is the cross-species candidate: Human, Mouse and Rat are listed as reactive, while its IHC dilution entry specifies Human and Rat and provides no IHC image caption (catalog: A10607 reactivity, dilution entry and image captions). Neither SKU lists IF/ICC or an IF image, so neither has catalog support for an IF/ICC recommendation (catalog: PA2092 and A10607 application lists and image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q13520 (AQP6_HUMAN, Aquaporin-6).
- Human Protein Atlas. AQP6 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. AQP6 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. AQP6 antibody validation summary (1 antibodies).
- Aquaporin-6 is expressed along the rat gastrointestinal tract and upregulated by feeding in the small intestine. BMC physiology 2009 — PMC2765416.
- Aquaporin-6 expression in the cochlear sensory epithelium is downregulated by salicylates. Journal of biomedicine & biotechnology 2010 — PMC2810475.
- Aquaporin 2 is differentially expressed in granulosa cells of various stages of human follicles and is regulated by luteinizing hormone. Frontiers in cell and developmental biology 2025 — PMC12399404.
- Expression of adrenergic and cholinergic receptors in murine renal intercalated cells. The Journal of veterinary medical science 2014 — PMC4272982.
- PubMed PMID:8812490 — UniProt-cited evidence.
- PubMed PMID:16541075 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for AQP6 (Aquaporin-6). Expected localisation Renal tubular cytoplasm (HPA tissue IHC); vesicle membrane (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: PA2092 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Kidney (Distal tubules); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet PA2092); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat-induced epitope retrieval in citrate buffer, pH 6.0 , 20 min at 95–98 °C…; 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-AQP6, 0.5-1μg/ml (datasheet PA2092); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific). Selected-image fixative and duration unreported (datasheet PA2092); verify before use.; Caveat: Presumed off-target staining may confound scoring (HPA tissue IHC); Isoform / epitope: No annotated isoforms; epitope side affects access (UniProt); Regulation: No expression regulator annotated (UniProt). Evidence: UniProt Q13520, HPA tissue IHC · Enhanced, HPA ICC-IF · Membrane, Datasheet PA2092, PMC2810475, PMC12399404. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/AQP6/immunohistochemistry-ihc-guide.