SIRT7 / NAD-dependent protein deacetylase sirtuin-7 · IHC design guide

Design Immunohistochemistry for SIRT7

Plan chromogenic SIRT7 IHC in paraffin sections using nuclear and nucleolar staining as the tissue reference (HPA tissue IHC). Colon glandular cells show medium staining, while adipocytes are reported as undetected; use them as contrasting tissue references (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for SIRT7 (IHC for SIRT7): expected localisation Nuclear and nucleolar tissue staining (HPA tissue IHC), antibody PB9358, validated IHC image, and IHC protocol steps — Printable **SIRT7** IHC protocol sheet — expected localisation Nuclear and nucleolar tissue staining (HPA tissue IHC), antibody PB9358, controls and protocol steps. Open the full SIRT7 IHC guide →

Navigate to: Protocols Staining pattern Controls Antibodies

SIRT7 Immunohistochemistry Experimental Design Guide

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

Must know before staining

	Expected localisation	Nuclear and nucleolar tissue staining (HPA tissue IHC)
	Staining pattern	Nuclear and nucleolar signal across many cell types (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet PB9358)
	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 paraffin-section fixation consistent across samples. (standard IHC practice; not target-specific)
	Caveat	Stress can move SIRT7 from nucleolus to nucleoplasm (UniProt)
	Regulation	Low tissue RNA specificity (HPA tissue RNA)
	Isoform / epitope	3 isoforms; antibody epitope coverage is unknown (UniProt)

Section 1

Recommended SIRT7 IHC & IF Protocols

The catalog antibody’s IHC-P protocol is supplemented by three published SIRT7 IHC protocols with usable method details (PMC5042897; PMC9687268; PMC11164202).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded mouse spleen tissue; fixative not specified (datasheet PB9358)
Fixation	Image fixative and duration unreported (datasheet PB9358); 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 PB9358); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet PB9358)
Primary antibody	Rabbit anti-SIRT7, 0.5-1μg/ml (datasheet PB9358)
Primary incubation	Overnight at 4 °C (datasheet PB9358)
Detection	HRP-conjugated secondary, DAB chromogen (datasheet PB9358)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	SIRT7-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Ubiquitous nuclear and nucleolar expression. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet: PB9358); the three published excerpts do not specify retrieval conditions (PMC5042897; PMC9687268; PMC11164202).

Section 2

What Is the Expected SIRT7 Staining Pattern?

SIRT7 is mainly nuclear, occupying the nucleolus and nucleoplasm (UniProt Q9NRC8); it has no transmembrane segment (UniProt Q9NRC8 topology). In paraffin sections, expect nuclear or nucleolar staining in many cell types, including medium staining in colon glandular cells and bronchial respiratory epithelial cells (HPA: tissue IHC). HPA calls the tissue pattern ubiquitous, but its IHC assessment has medium consistency with RNA data and awaits external verification (HPA: tissue IHC, Approved).

What am I looking at on my slide?
Nuclear staining, with nucleolar emphasis, in colon glandular cells or bronchial respiratory epithelial cells (HPA: tissue IHC, Medium).	This fits the reported IHC distribution (HPA: tissue IHC) and SIRT7's main nucleolar and nucleoplasmic localisation (UniProt Q9NRC8). Judge the pattern in identified cells; a medium HPA level describes the reported staining and does not set a required intensity for every section (HPA: tissue IHC).
Predominantly cytoplasmic staining, with little nuclear signal.	Reassess specificity and detection conditions: predominantly cytoplasmic staining conflicts with the main nuclear pattern (HPA: tissue IHC; UniProt Q9NRC8). Cytoplasmic localisation is also annotated, near the nuclear membrane (UniProt Q9NRC8), so a limited cytoplasmic component alone does not establish an artefact.
Strong staining in adipocytes, while expected nuclear staining is absent (HPA: adipocytes, Not detected).	Consider cross-reactivity or endogenous detection activity, particularly if the signal lacks nuclear localisation (general IHC practice; UniProt Q9NRC8). HPA's result applies to adipocytes, not every cell in adipose tissue (HPA: tissue IHC). Confirm the stained cell type before treating this as a discordant result.
Diffuse colour across nuclei, cytoplasm and cell-free areas.	Diffuse deposition obscures the compartment needed to interpret SIRT7 (UniProt Q9NRC8; HPA: tissue IHC). Assess background with a no-primary control and inspect blocking, washing and detection conditions (general IHC practice). This appearance alone cannot establish genuine SIRT7 expression.
No nuclear signal in colon glandular cells despite an intact section (HPA: colon glandular cells, Medium).	Investigate the assay before calling the sample negative: HPA reports staining in these cells, although its IHC assessment is Approved with medium RNA concordance and pending external verification (HPA: tissue IHC). Check section quality and the staining run with appropriate controls (general IHC practice).

💡Expected SIRT7 appearanceA credible IHC positive shows nuclear staining, potentially concentrated in nucleoli, in correctly identified colon glandular or bronchial respiratory epithelial cells at a level consistent with HPA's Medium observations; diffuse cell-free colour or dominant cytoplasmic staining warrants investigation (HPA: tissue IHC; UniProt Q9NRC8; general IHC practice).

How each factor affects the staining
Which compartment should guide scoring?	Use nuclear and nucleolar localisation as the main IHC guide (HPA: tissue IHC; UniProt Q9NRC8). UniProt also annotates nucleoplasm and limited cytoplasmic localisation (UniProt Q9NRC8). Score nuclear signal in the relevant cells before interpreting a secondary pattern.
Which cells offer an interpretable comparison?	HPA reports Medium staining in colon glandular and bronchial respiratory epithelial cells, Low in duodenal glandular cells, and Not detected in adipocytes (HPA: tissue IHC). These are cell-level observations; do not assign one expected result to every cell in a tissue.
How strong is the IHC evidence?	Two listed antibodies have IHC status Approved (HPA: HPA053669 and CAB037261). HPA reports medium consistency between staining and RNA expression and notes pending external verification (HPA: tissue IHC). Treat a matching pattern as supporting evidence, then assess assay controls and morphology.
Can isoforms or processing explain a different pattern?	UniProt lists three SIRT7 isoforms, a 1–400 chain, and no signal peptide or propeptide (UniProt Q9NRC8). No antibody epitope or isoform-specific IHC behaviour is supplied; these annotations cannot explain a particular staining difference without further evidence.
What should IF/ICC show?	HPA reports mainly nucleoplasmic signal with additional nuclear speckles in ICC-IF (HPA: subcellular, supported). UniProt also places SIRT7 in the nucleolus (UniProt Q9NRC8). This IF/ICC observation helps interpret localisation; it does not prescribe an IF protocol or establish identical appearance in paraffin IHC.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
No signal in an HPA Medium cell population (HPA: colon glandular cells).	The run may lack usable antigen detection, or the sampled cells may be misidentified (general IHC practice). HPA's Approved call has medium consistency and awaits external verification (HPA: tissue IHC).	Verify morphology and controls, then review retrieval and detection conditions using general IHC practice; no SIRT7-specific retrieval or fixation effect is established here.
Predominantly cytoplasmic colour with weak nuclei.	This conflicts with the main nuclear distribution (UniProt Q9NRC8; HPA: tissue IHC), though UniProt also annotates cytoplasmic localisation near the nuclear membrane (UniProt Q9NRC8).	Check a no-primary control and compare nuclear staining in an HPA Medium cell population (HPA: tissue IHC; general IHC practice). Interpret a small cytoplasmic component separately.
Unexpected positive staining in adipocytes (HPA: adipocytes, Not detected).	Cell misidentification, cross-reactivity or endogenous detection activity may explain the discordance (general IHC practice); HPA's negative observation is specific to adipocytes (HPA: tissue IHC).	Confirm cell identity and compartment, inspect the no-primary control, and compare a reported Medium cell population in the same run (HPA: tissue IHC; general IHC practice).
Diffuse colour obscures nuclear detail.	Background from staining or detection can prevent compartment assessment (general IHC practice); SIRT7's expected main localisation is nuclear (UniProt Q9NRC8).	Review blocking, washing and detection controls, then assess whether identifiable nuclei show a discrete pattern (general IHC practice; HPA: tissue IHC).
Nuclear staining varies between cell types in one tissue.	HPA reports staining by cell population, including Not detected alveolar cells and Medium bronchial respiratory epithelial cells (HPA: tissue IHC). A tissue-wide average can conceal this distinction.	Score morphologically identified cell populations separately and compare each with its own HPA observation (HPA: tissue IHC; general IHC practice).
Nucleolar and nucleoplasmic emphasis differs between samples.	SIRT7 occupies both compartments and can move from nucleolus to nucleoplasm in response to stress (UniProt Q9NRC8). The staining pattern alone does not establish that stress occurred.	Record the compartments separately, confirm a discrete nuclear signal and check run controls before interpreting the difference biologically (UniProt Q9NRC8; general IHC practice).

Source: UniProt Q9NRC8 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing SIRT7 staining

IHC analysis of SIRT7 using anti-SIRT7 antibody (PB9358). SIRT7 was detected in a paraffin-embedded section of mouse spleen 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 1 μg/ml rabbit anti-SIRT7 Antibody (PB9358) 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.

PB9358 · IHCIHC analysis of SIRT7 using anti-SIRT7 antibody (PB9358). SIRT7 was detected in a paraffin-embedded section of mouse spleen tissue. Heat med

IHC analysis of SIRT7 using anti-SIRT7 antibody (PB9358). SIRT7 was detected in a paraffin-embedded section of rat spleen 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 1 μg/ml rabbit anti-SIRT7 Antibody (PB9358) 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.

PB9358 · IHCIHC analysis of SIRT7 using anti-SIRT7 antibody (PB9358). SIRT7 was detected in a paraffin-embedded section of rat spleen tissue. Heat media

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000187531-SIRT7/tissue/cerebral+cortex#imid_16689599

HPA · EsophagusHuman Protein Atlas IHC, Esophagus. Source: https://www.proteinatlas.org/ENSG00000187531-SIRT7/tissue/esophagus#imid_16689579

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000187531-SIRT7/tissue/colon#imid_16690109

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000187531-SIRT7/tissue/liver#imid_16690094

HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA027284; green = SIRT7, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for SIRT7 IHC & IF

🧪Run breast first: glandular cells should show SIRT7 staining (HPA: Medium in breast glandular cells). Run adipose tissue as the negative, where adipocytes are not detected (HPA: Not detected in adipocytes); on the breast slide, use adjacent nonglandular cells as an internal background comparator, without assigning them an HPA negative level (HPA: breast level applies to glandular cells).

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

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SIRT7 in HEK293, U-251MG, U2OS, A-549, PC-3, NIH 3T3, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).

Technical controls: Include a no-primary (secondary-only) section, a concentration-matched rabbit isotype control, and SIRT7 knockout tissue where available (selected-SKU caption: rabbit primary; standard IHC controls). Quench endogenous peroxidase and inspect background before interpreting HRP/DAB staining (selected-SKU caption: HRP/DAB; standard chromogenic IHC practice).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). Heat retrieval in EDTA at pH 8.0 was used, but its necessity was not tested in the supplied evidence (selected-SKU caption: heat-mediated EDTA retrieval). Neither frozen sections nor IF/ICC are established as easier here; IF/ICC images support nucleoplasmic localization, while adipocytes in the proposed breast section require careful background interpretation (HPA subcellular: nucleoplasm supported; HPA: breast glandular cells Medium; HPA: adipose adipocytes Not detected).

HPA tissue IHC evidence for SIRT7

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — 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
Adrenal gland	Glandular cells	Medium	Protein (IHC)	HPA →
Breast	Glandular cells	Medium	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	Medium	Protein (IHC)	HPA →
Caudate	Glial 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 →
Liver	Cholangiocytes	Not detected	Protein (IHC)	HPA →
Lung	Alveolar cells	Not detected	Protein (IHC)	HPA →
Ovary	Ovarian stroma cells	Not detected	Protein (IHC)	HPA →
Parathyroid gland	Glandular cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced SIRT7 IHC Tips

Troubleshoot SIRT7 staining in paraffin sections by checking retrieval, nuclear localisation, assay controls and cell specific scoring.

How should I retrieve SIRT7 in paraffin sections when nuclear staining is weak?

Start with heat mediated retrieval in EDTA at pH 8.0 for the IHC validated antibody (datasheet PB9358). The selected paraffin section example used that retrieval before 1 μg/ml primary antibody overnight at 4°C (caption PB9358). If nuclear staining is weak, compare a carefully titrated alternative retrieval condition on serial sections while holding antibody concentration and detection constant; treat any improvement as an assay optimisation, not established SIRT7 specificity. Inspect tissue integrity and compare nucleolar or nucleoplasmic staining with a no primary control, because SIRT7 is mainly nuclear and nucleolar (UniProt Q9NRC8 subcellular; HPA tissue IHC profile).

Could fixation explain weak or uneven SIRT7 staining?

Target specific fixation sensitivity is unknown: the selected mouse spleen caption identifies a paraffin section but does not state its fixative (caption PB9358). Record fixative, fixation duration and processing history for each specimen, then compare similarly processed sections before attributing differences to SIRT7 abundance. If staining is patchy, inspect morphology and test serial sections with the same EDTA pH 8.0 retrieval and antibody conditions used in the selected example (datasheet PB9358; caption PB9358). Use a no primary control and a tissue section with interpretable nuclear staining to assess the run; staining patterns alone cannot establish a SIRT7 specific fixation effect.

What compartment should count as convincing SIRT7 staining?

Prioritise signal within intact nuclei, including nucleoli and nucleoplasm, because SIRT7 mainly occupies those compartments (UniProt Q9NRC8 subcellular; HPA tissue IHC profile). Its distribution can shift from nucleolus to nucleoplasm during stress, so a less prominent nucleolar pattern does not by itself exclude genuine staining (UniProt Q9NRC8 subcellular). Score nuclear and cytoplasmic chromogen separately, using a nuclear counterstain and consistent section thickness to define compartment boundaries. Predominantly diffuse cytoplasmic staining warrants scrutiny against no primary and adjacent tissue controls, although cytoplasmic SIRT7 has been reported near the nuclear membrane (UniProt Q9NRC8 subcellular).

How do isoforms and epitope placement affect interpretation of SIRT7 IHC?

SIRT7 has 3 annotated isoforms and a sirtuin type catalytic domain spanning residues 82–329 (UniProt Q9NRC8 isoforms; UniProt Q9NRC8 domains). The payload does not map the catalog antibody epitope, so staining cannot establish which isoform is present or whether the catalytic region is represented. An annotated alternative methylation site at residue 388 makes epitope placement relevant to possible recognition, but its effect on this antibody has not been shown (UniProt Q9NRC8 modified residues). If an epitope map becomes available, compare it with isoform sequences and that site; meanwhile, interpret chromogen as antibody reactivity rather than isoform specific abundance.

How can I use IF to check SIRT7 localisation alongside a cell type marker?

For an IF follow up, pair SIRT7 with a marker of the expected cell population, such as an epithelial marker when examining colon glandular cells, which show medium tissue IHC staining (HPA tissue IHC: colon glandular cells, Medium). Select spectrally separated fluorophores, favour a far red channel if the specimen autofluoresces, and inspect unstained and single stain controls before interpreting overlap. Because the expected signal lies inside the nucleus and SIRT7 has no transmembrane segment, optimise permeabilisation for access to the nuclear epitope while preserving morphology (UniProt Q9NRC8 subcellular; UniProt Q9NRC8 topology). Compare nuclear and nucleolar patterns across cells; HPA IF also supports nucleoplasmic and nuclear speckle localisation (HPA subcellular).

How do I separate SIRT7 chromogen from nonspecific background?

Review a no primary section first, then compare it with the test section under identical chromogen development and counterstaining conditions. The selected paraffin section example used 10% goat serum blocking, 1 μg/ml primary antibody overnight at 4°C, and DAB detection (caption PB9358). Peroxidase blocking is a general chromogenic IHC step; evaluate its adequacy when brown signal appears outside intact cells or persists without primary antibody. If background remains high, titrate primary antibody and detection strength while preserving the EDTA pH 8.0 retrieval reference condition, then reassess the expected nuclear pattern (datasheet PB9358; UniProt Q9NRC8 subcellular).

How should I quantify SIRT7 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the scored cell population and compartment before analysis, then report the percentage of positive nuclei and a nuclear H score using fixed intensity thresholds. Record nucleolar and nucleoplasmic patterns separately if redistribution matters, since SIRT7 can move from nucleolus to nucleoplasm under stress (UniProt Q9NRC8 subcellular). Normalise positive cell counts to all evaluable cells of the same type, or express positive cell density per mm² of viable tissue when cell density varies. Keep retrieval, chromogen exposure and counterstaining consistent across sections; report exclusions for folds, edges and necrosis so technical differences do not drive apparent SIRT7 changes.

When is an apparent SIRT7 positive signal likely to be artefact?

A credible result should show signal in intact nuclei, often nucleolar or nucleoplasmic, with a plausible cell distribution (UniProt Q9NRC8 subcellular; HPA tissue IHC profile). Check whether staining instead clusters at section edges, necrotic regions or sites that remain brown without primary antibody; these patterns warrant investigation of processing or endogenous enzyme activity. Compare cell types explicitly: HPA reports medium staining in colon glandular cells but no detection in adipocytes, while its tissue IHC rating remains Approved with medium RNA concordance and pending external verification (HPA tissue IHC). Treat a discordant compartment or cell pattern as a prompt for controls and independent validation, not proof of SIRT7 expression.

Boster reagents

Best SIRT7 / NAD-dependent protein deacetylase sirtuin-7 IHC Antibodies

PB9358 has real SIRT7 IHC images from mouse and rat paraffin sections; its catalog lists human, mouse and rat reactivity (PB9358 image captions; catalog reactivity). No IF data are supplied (catalog IF images).

Real IHC data

Anti-SIRT7 Antibody ®

Cat # PB9358

View product →

PB9358 is the only SKU supplied and is listed for IHC, with human, mouse and rat reactivity (catalog applications and reactivity). Its IHC images show SIRT7 staining in mouse and rat spleen paraffin sections (PB9358 image captions).

Which to pick: Choose PB9358 for paraffin-section IHC: its mouse and rat spleen images use heat retrieval in EDTA at pH 8.0 and 1 μg/ml primary antibody (PB9358 image captions). PB9358 is listed as reactive with human, mouse and rat, although the supplied IHC images show only mouse and rat; the fixative is unreported (catalog reactivity; PB9358 image captions). No IF/ICC antibody can be recommended from this payload because PB9358 has no listed IF application, dilution or image (catalog applications and IF fields).

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

References

UniProt Consortium. UniProt entry Q9NRC8 (SIR7_HUMAN, NAD-dependent protein deacetylase sirtuin-7).
Human Protein Atlas. SIRT7 tissue IHC expression (reliability: Approved).
Human Protein Atlas. SIRT7 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the nuclear speckles..
Human Protein Atlas. SIRT7 antibody validation summary (4 antibodies).
Sirtuin 7: a new marker of aggressiveness in prostate cancer. Oncotarget 2017 — PMC5652781.
SIRT7, H3K18ac, and ELK4 Immunohistochemical Expression in Hepatocellular Carcinoma. Journal of pathology and translational medicine 2016 — PMC5042897.
Sirtuin 7 Inhibitor Attenuates Colonic Mucosal Immune Activation in Mice-Potential Therapeutic Target in Inflammatory Bowel Disease. Biomedicines 2022 — PMC9687268.
Analysis of the Expression and Prognostic Value of SIRTs in Hepatocellular Carcinoma. International journal of general medicine 2024 — PMC11164202.
PubMed PMID:10873683 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:16625196 — UniProt-cited evidence.