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SIRT1 / NAD-dependent protein deacetylase sirtuin-1 · IHC design guide
Design Immunohistochemistry for SIRT1
Plan SIRT1 IHC-P around nuclear staining in several tissues, with high signal reported in adrenal glandular and lymph node germinal center cells (HPA tissue IHC). Score nuclear signal by cell type and use controls to assess unexpected staining, given the report of presumed off-target binding (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SIRT1 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 staining observed in several tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining across several tissues (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image M00018-2) | |
| Caveat | Presumed off-target staining may confound scoring (HPA tissue IHC) | |
| Regulation | Expression regulation is not specified (UniProt) | |
| Isoform / epitope | 2 isoforms and a 2–533 fragment; epitope coverage is unknown (UniProt) |
Section 1
Recommended SIRT1 IHC & IF Protocols
The catalog antibody protocol is accompanied by one published SIRT1 IHC protocol for human articular cartilage (PMC5116180).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet M00018-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear antigen) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-SIRT1, 1:100-1:200 (datasheet M00018-2) |
| 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 | SIRT1-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in several tissues. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 retrieval at 95–98 °C for 20 min (page antigen retrieval). Verify the published secondary antibody: it is anti-mouse despite a rabbit primary (PMC5116180).
Section 2
What Is the Expected SIRT1 Staining Pattern?
SIRT1 should stain predominantly in nuclei in paraffin sections, especially adrenal glandular cells, lymph node germinal center cells, and cells in testicular seminiferous ducts (HPA: High; nuclear expression in several tissues). Cytoplasmic staining can occur, but SIRT1 has no transmembrane segment (UniProt Q96EB6: localization and topology). Treat unexpected staining cautiously: HPA rates tissue IHC Approved with medium staining–RNA consistency and notes presumed off-target binding.
| Clear nuclear chromogen in adrenal glandular cells, lymph node germinal center cells, or cells in seminiferous ducts (HPA: High). | This matches the reported IHC distribution and predominant nuclear pattern (HPA: tissue IHC). Compare the signal with adjacent cells and the negative control before scoring it as SIRT1 (general IHC practice). |
| Strong, widespread cytoplasmic staining with little or no nuclear signal. | This conflicts with the predominant nuclear IHC pattern (HPA: tissue IHC). Cytoplasmic SIRT1 is possible (UniProt Q96EB6: localization), so judge this pattern against a known-positive section and background controls rather than rejecting every cytoplasmic signal. |
| Prominent staining in alveolar cells or adipocytes, with weak staining in an expected positive population. | HPA reports alveolar cells and adipocytes as Not detected in its sampled tissues (HPA: tissue IHC). Cross-reactivity or endogenous chromogenic activity is possible (general IHC practice); the HPA result does not prove these cells can never express SIRT1. |
| Diffuse chromogen over cells and extracellular areas, without identifiable nuclear boundaries. | A field-wide deposit cannot establish the reported nuclear distribution (HPA: tissue IHC). Review the negative control, blocking, wash stringency, and detection chemistry to locate nonspecific staining (general IHC practice). |
| No nuclear signal in a section containing expected positive cells. | First confirm that the relevant cells are present: adrenal glandular, lymph node germinal center, and seminiferous duct cells are reported High (HPA: tissue IHC). Then review assay controls and IHC-P handling (general IHC practice); one negative slide does not establish SIRT1 absence. |
💡Expected SIRT1 appearanceCall a section positive when defined nuclei stain in expected cell populations, with conspicuous signal in HPA High populations; diffuse deposits or strong staining confined to HPA Not detected populations warrant review (HPA: tissue IHC; general IHC practice).
| Compartment and topology | Nuclear staining is the main tissue IHC expectation (HPA: tissue IHC). UniProt also lists cytoplasm, PML bodies, nucleoplasm, and mitochondrion, with no transmembrane segment (UniProt Q96EB6: localization and topology); a membrane outline is therefore unexpected. |
| Cell population and tissue context | HPA calls adrenal glandular cells, lymph node germinal center cells, and seminiferous duct cells High; marrow hematopoietic and placental decidual cells are Medium (HPA: tissue IHC). Score the identified cell population, since neighboring populations need not share its staining category. |
| Antibody evidence | HPA006295 and CAB003855 have Approved IHC status, while HPA006295 and HPA052351 have Supported ICC status (HPA: antibody validation). HPA's tissue IHC summary still reports medium staining–RNA consistency and presumed off-target binding; validation does not make every positive deposit specific. |
| Isoforms and processing | UniProt lists two isoforms and chains spanning residues 2–747 and 2–533 (UniProt Q96EB6: isoforms and processing). The supplied evidence gives no antibody epitope, so it cannot establish which forms a particular IHC stain detects or explain a negative slide. |
| What should IF/ICC show? | Mainly nucleoplasmic signal, with additional nucleoli fibrillar center, mitochondrial, and cytosolic localization reported (HPA: subcellular ICC-IF). This is an IF/ICC interpretation cue; tissue IHC still has a predominantly nuclear expectation (HPA: tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive cells are unstained. | The positive population may be absent from the section, or the assay may have failed (HPA: High populations; general IHC practice). | Verify cell identity and section integrity, then check positive and negative controls and review the IHC-P retrieval and detection workflow (general IHC practice). |
| Signal appears only in cytoplasm. | Cytoplasmic localization is possible, but a cytoplasm-only tissue pattern differs from HPA's nuclear IHC profile (UniProt Q96EB6: localization; HPA: tissue IHC). | Compare nuclear counterstain and matched controls; assess whether cytoplasmic signal exceeds nonspecific background (general IHC practice). |
| Many HPA Not detected cells stain strongly. | Off-target staining is plausible because HPA reports presumed off-target binding in its tissue assessment (HPA: tissue IHC). Endogenous detection activity is another general IHC possibility. | Inspect a negative control and repeat with an independently validated antibody if available (general IHC practice; HPA: IHC Approved antibodies). |
| The whole section has hazy chromogen. | Poorly localized background can arise from blocking, washing, or detection conditions (general IHC practice). | Check reagent-only or primary-omission controls, wash steps, and chromogen development; score nuclei only after the background is resolved (general IHC practice). |
| A Medium or Low population stains less than a High population. | HPA reports differing cell-level staining categories across tissues (HPA: tissue IHC). | Use the appropriate cell population as the comparator and avoid calling a weak section negative solely because another tissue stains more strongly (HPA: tissue IHC; general IHC practice). |
| Different antibodies give different patterns. | HPA reports Approved IHC validation but also medium staining–RNA consistency and presumed off-target binding (HPA: antibody validation and tissue IHC). Epitope information is absent from the supplied evidence. | Compare matched sections, controls, and cell-level localization; report the antibody identifier and unresolved discrepancy (general IHC practice). |
Experiment evidence
IHC & IF images showing SIRT1 staining
M00018-2 · IHCMouse testis was stained with Anti-SIRT1 rabbit antibody
M00018-2 · IHCHuman testis was stained with Anti-SIRT1 rabbit antibody
M00018 · IHCImmunohistochemical analysis of paraffin-embedded human kidney, using SIRT1 Antibody.
M00018 · IFImmunofluorescent analysis of Hela cells, using SIRT1 Antibody .
A00018-1 · IFIF analysis of SIRT1 using anti-SIRT1 antibody (A00018-1) and anti-Beta Tubulin antibody (M01857-3). SIRT1 was detected in immunocytochemica
PB9159 · IFIF analysis of SIRT1 using anti-SIRT1 antibody (PB9159). SIRT1 was detected in an immunocytochemical section of A431 cells. Enzyme antigen r
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000096717-SIRT1/tissue/cerebral+cortex#imid_2075312
HPA · Adrenal glandHuman Protein Atlas IHC, Adrenal gland. Source: https://www.proteinatlas.org/ENSG00000096717-SIRT1/tissue/adrenal+gland#imid_2075296
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000096717-SIRT1/tissue/colon#imid_2075230
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000096717-SIRT1/tissue/liver#imid_2075239
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA052351; green = SIRT1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA052351; green = SIRT1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SIRT1 IHC & IF
🧪Run testis first and expect staining in cells of the seminiferous ducts (HPA: High in cells in seminiferous ducts). Use adipose tissue adipocytes as the biological low-signal comparison (HPA: Not detected in adipocytes); on the testis slide, assess background in neighboring cells, but do not assume they are SIRT1-negative without validation (HPA: testis row identifies only cells in seminiferous ducts).
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SIRT1 in A-431, U-251MG, U2OS, SiHa, NIH 3T3, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and a concentration-matched rabbit isotype control for the captioned rabbit antibody (caption: rabbit antibody), plus SIRT1 knockout tissue where available or a validated immunizing-peptide block. For chromogenic testis IHC, quench endogenous peroxidase and, if using avidin–biotin detection, block endogenous biotin (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected M00018-2 mouse-testis caption leaves the fixative unreported (caption: fixative not stated). Retrieval dependency is unreported; compare heat-induced retrieval conditions with a no-retrieval section during IHC-P optimization (standard IHC practice). The supplied evidence does not establish that frozen sections or IF are easier, or document a testis-specific artefact; inspect seminiferous-duct lumens and section edges for background (HPA: High in cells in seminiferous ducts; standard IHC practice).
HPA tissue IHC evidence for SIRT1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Lymph node | Germinal center cells | High | Protein (IHC) | HPA → |
| Testis | Cells in seminiferous ducts | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Placenta | Decidual cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Cerebral cortex | Endothelial cells | Not detected | Protein (IHC) | HPA → |
| Epididymis | Glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SIRT1 IHC Tips
Troubleshoot SIRT1 staining in paraffin sections by checking retrieval, cell identity, subcellular pattern and controls before interpreting chromogenic signal.
How should I adjust retrieval when nuclear SIRT1 staining is weak?
Start with Tris-EDTA at pH 9.0, heated to 95–98 °C for 20 min (page retrieval specification). Compare a positive control section in the same run, such as testis cells in seminiferous ducts, where high staining is reported (HPA: testis tissue IHC). If nuclear signal remains weak, test a shorter or longer heating period on adjacent sections while keeping the buffer and detection conditions constant; excessive heating can damage section morphology (standard IHC practice). Record nuclear signal and tissue integrity together, because SIRT1 is predominantly nuclear in tissue staining, although other locations are documented (HPA: tissue IHC profile; UniProt Q96EB6 subcellular location).
Could fixation explain weak or patchy SIRT1 staining in paraffin sections?
SIRT1-specific fixation sensitivity is unknown from the supplied evidence; the selected mouse testis caption does not state its fixative (M00018-2 tissue IHC caption). Record fixative, fixation duration and processing history for each specimen, then compare sections processed alike before changing antibody concentration (standard IHC practice). Include a same-run positive control and inspect nuclear preservation, since nuclear staining is the reported tissue pattern (HPA: tissue IHC profile). If sections from one processing batch stain poorly, assess section adhesion, retrieval and detection alongside fixation records; neither the reported tissue pattern nor SIRT1 modifications establish a particular fixation effect (standard IHC practice; UniProt Q96EB6 modified residues).
How should I assess cytoplasmic or punctate staining alongside nuclear SIRT1?
Score nuclear staining first, because tissue IHC reports nuclear expression and cell imaging supports nucleoplasmic localisation (HPA: tissue IHC profile; HPA: subcellular localisation). SIRT1 also has reported cytoplasmic, mitochondrial and PML-body locations, so an additional compartment is biologically plausible but needs independent confirmation in the specimen (UniProt Q96EB6 subcellular location). Compare the pattern across matched sections, cell types and controls, checking whether pigment or diffuse chromogen obscures nuclear boundaries (standard IHC practice). Report nuclear and extranuclear staining separately, with the fraction of affected cells, rather than treating any brown deposit as equivalent SIRT1 expression (standard IHC scoring practice).
Can epitope choice change which SIRT1 species this stain detects?
SIRT1 has 2 annotated isoforms, a deacetylase domain at residues 236–496, and an annotated 2–533 fragment (UniProt Q96EB6 isoforms, domains and processing). The supplied caption does not specify the catalog antibody's epitope, so its coverage of either isoform or the fragment cannot be assigned from these records (M00018-2 tissue IHC caption). Check the antibody's documented immunogen or epitope before comparing its staining with another reagent; an epitope outside the fragment could change what is detectable (standard immunostaining practice; UniProt Q96EB6 processing). Keep retrieval and detection matched when comparing antibodies, and describe discordant staining as an observation until epitope coverage and specificity are established (standard IHC practice).
How can IF help check a disputed SIRT1 IHC localisation pattern?
On a companion IF section, multiplex SIRT1 with a validated marker for the cell population under study and a nuclear counterstain, then compare cell identity and compartment patterns with IHC (standard IF practice). Choose spectrally separated fluorophores after checking tissue autofluorescence in an unstained section, especially where weak cytoplasmic signal is in question (standard IF practice). SIRT1 has no transmembrane segment and is mainly nucleoplasmic in cell imaging, so use controlled permeabilisation to expose an intracellular epitope and confirm the antibody's documented epitope if available (UniProt Q96EB6 topology; HPA: subcellular localisation; standard IF practice). Include single-label and secondary-only controls to assess bleed-through and nonspecific fluorescence (standard IF practice).
What should I check when SIRT1 chromogen covers most of the section?
First compare secondary-only and no-primary controls with the stained section to identify detection background, then inspect whether signal follows cell nuclei (standard IHC practice; HPA: tissue IHC profile). For peroxidase-based chromogenic detection, verify the endogenous peroxidase block and distinguish residual enzyme activity from specific DAB deposition (standard IHC practice). Titrate the primary antibody and detection reagent on serial sections while holding retrieval constant, and check whether longer development increases diffuse staining (standard IHC practice). Interpret widespread color cautiously: HPA reports presumed off-target binding in its tissue assessment, while SIRT1 RNA has low tissue specificity, so neither breadth nor intensity alone proves specificity (HPA: tissue IHC reliability and RNA specificity).
How should I quantify SIRT1 IHC across specimens with different cellularity? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because tissue IHC reports nuclear expression while other SIRT1 locations are also annotated (HPA: tissue IHC profile; UniProt Q96EB6 subcellular location). Within each predefined region, record the percentage of positive target-cell nuclei and staining intensity, then calculate an H-score using intensity categories 0–3 if that scale fits the study design (standard IHC scoring practice). Normalize counts to the number of eligible target cells, or report positive-cell density per mm² of viable tissue when spatial distribution matters (standard histologic quantification practice). Apply one threshold, imaging setup and exclusion rule across specimens, and report extranuclear signal separately (standard IHC scoring practice).
How can I distinguish genuine SIRT1 staining from artefact?
A credible pattern should identify intact cells and usually include nuclear signal, consistent with reported nuclear tissue staining and supported nucleoplasmic localisation (HPA: tissue IHC profile; HPA: subcellular localisation). Compare the stained cell population with an expected positive reference, such as cells in testis seminiferous ducts, and assess negative controls in the same run (HPA: testis tissue IHC; standard IHC practice). Be cautious when color is confined to cut edges, necrotic areas or structures lacking cell boundaries, or persists in no-primary controls; check endogenous peroxidase blocking where relevant (standard IHC practice). Additional cytoplasmic or mitochondrial signal warrants corroboration because those locations are documented, while HPA also notes presumed off-target tissue binding (UniProt Q96EB6 subcellular location; HPA: tissue IHC reliability).
Boster reagents
Best SIRT1 / NAD-dependent protein deacetylase sirtuin-1 IHC Antibodies
Validated anti-SIRT1 antibodies have IHC images from mouse testis and human kidney and IF images from HeLa and A431 cells (catalog image captions). Listed reactivity covers human and rat (catalog: reactivity).
Real IHC data
Anti-SIRT1 Rabbit Monoclonal Antibody
Cat # M00018-2
Real IHC data
Anti-SIRT1 Monoclonal Antibody
Cat # M00018
Real IF data
Anti-SIRT1 Antibody ®
Cat # A00018-1
Real IF data
Anti-SIRT1 Antibody ®
Cat # PB9159
M00018-2 shows IHC staining of mouse testis, although mouse reactivity is unlisted; M00018 shows IHC staining of paraffin-embedded human kidney (catalog image captions; catalog: reactivity). A00018-1 shows IF in HeLa cells, and PB9159 shows IF in A431 cells (catalog image captions).
Which to pick: For tissue IHC, choose the rabbit monoclonal M00018 for human paraffin sections (catalog: clonality and human reactivity; M00018 IHC image caption: paraffin-embedded human kidney); its fixative is unreported (M00018 IHC image caption). For IF/ICC, A00018-1 and PB9159 both list human IF/ICC and show cell images (catalog: applications and reactivity; respective IF image captions). For listed human and rat reactivity, choose rabbit monoclonal M00018-2, which lists IHC and IF; its IHC image shows mouse testis, while mouse reactivity and the fixative are unreported (catalog: clonality, applications and reactivity; M00018-2 IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q96EB6 (SIR1_HUMAN, NAD-dependent protein deacetylase sirtuin-1).
- Human Protein Atlas. SIRT1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. SIRT1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the nucleoli fibrillar center, cytosol and mitochondria..
- Human Protein Atlas. SIRT1 antibody validation summary (3 antibodies).
- Dual miRNA-Mediated Axes Act in Concert in the Antioxidant Action of Eicosapentaenoic Acid: let-7c-3p/TFAM Drives Mitochondrial Biogenesis While miR-34c-5p/SIRT1 Potentiates Enzymatic Defenses. Cell biochemistry and function 2026 — PMC13551511.
- Yangjingzhongyu Decoction regulates primordial follicle initiation via LncRNA-Smad1/AMPK dual pathways in diminished ovarian reserve. Journal of ovarian research 2026 — PMC12870358.
- Buyang Huanwu Decoction alleviates cerebral ischemic injury through modulating caveolin-1-mediated mitochondrial quality control. Frontiers in pharmacology 2023 — PMC10206009.
- The expression of SIRT1 in articular cartilage of patients with knee osteoarthritis and its correlation with disease severity. Journal of orthopaedic surgery and research 2016 — PMC5116180.
- PubMed PMID:10381378 — UniProt-cited evidence.
- PubMed PMID:12535671 — UniProt-cited evidence.
- PubMed PMID:15164054 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SIRT1 (NAD-dependent protein deacetylase sirtuin-1). Expected localisation Nuclear staining observed in several tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: M00018-2 at 1:100-1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); 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 M00018-2); 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 Tris-EDTA buffer, pH 9.0 , 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-SIRT1, 1:100-1:200 (datasheet M00018-2); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image M00018-2); Caveat: Presumed off-target staining may confound scoring (HPA tissue IHC); Isoform / epitope: 2 isoforms and a 2–533 fragment; epitope coverage is unknown (UniProt); Regulation: Expression regulation is not specified (UniProt). Evidence: UniProt Q96EB6, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet M00018-2, PMC5116180. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SIRT1/immunohistochemistry-ihc-guide.