SSTR1 / Somatostatin receptor type 1 · IHC design guide

Design Immunohistochemistry for SSTR1

Plan SSTR1 paraffin-section IHC with catalog antibody PA1693 at 0.5–1 μg/ml (datasheet: PA1693). Use duodenal, small-intestinal or stomach glandular cells as positive references, and assess membranous and cytoplasmic staining (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for SSTR1 (IHC for SSTR1): expected localisation Membranous and cytoplasmic staining (HPA tissue IHC), antibody PA1693, validated IHC image, and IHC protocol steps — Printable **SSTR1** IHC protocol sheet — expected localisation Membranous and cytoplasmic staining (HPA tissue IHC), antibody PA1693, controls and protocol steps. Open the full SSTR1 IHC guide →

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SSTR1 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	Membranous and cytoplasmic staining (HPA tissue IHC)
	Staining pattern	Glandular cells show membranous and cytoplasmic staining (HPA tissue IHC)
	Antigen retrieval	Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen)
	Positive control ⓘ	Duodenum+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 fixation consistent across sections. (standard IHC practice; not target-specific)
	Caveat	Antibody staining has low concordance with RNA (HPA tissue IHC)
	Regulation	Regulation is not established (UniProt)
	Isoform / epitope	No annotated isoforms; extracellular versus cytoplasmic epitope matters (UniProt)

Section 1

Recommended SSTR1 IHC & IF Protocols

The catalog antibody’s IHC-P protocol is followed by published SSTR1 IHC methods for pituitary adenoma and fibrotic myocardium (PMC6304820; PMC11262693).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Tissue sections; selected-image fixative not specified (standard IHC workflow)
Fixation	Image fixative and duration unreported (datasheet PA1693); 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-SSTR1, 0.5-1μg/ml (datasheet PA1693)
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	SSTR1-positive staining in glandular cells of duodenum (HPA tissue IHC: High). HPA tissue profile: Membranous and cytoplasmic expression in several tissues, most abundant in gastrointestinal tract. No signal in the no-primary control.

💡Decision noteStart with citrate pH 6.0 HIER at 95–98 °C for 20 min (page antigen retrieval); optimize against the published retrieval conditions if needed (PMC6304820; PMC11262693).

Section 2

What Is the Expected SSTR1 Staining Pattern?

SSTR1 is a cell-membrane receptor with 7 transmembrane segments (UniProt P30872 topology). In paraffin-section IHC, expect membranous and cytoplasmic staining, especially in gastrointestinal glandular cells (HPA: tissue IHC). HPA rates duodenal, small-intestinal and stomach glandular-cell staining High (HPA: tissue IHC). Its IHC profile is Approved, with low consistency between antibody staining and RNA expression; interpret individual signals cautiously (HPA: IHC reliability).

What am I looking at on my slide?
Membranous staining with some cytoplasmic signal in duodenal, small-intestinal or stomach glandular cells.	This matches the reported IHC pattern and the strongest listed glandular-cell results (HPA: tissue IHC). Membrane association is consistent with the receptor's 7-segment topology (UniProt P30872 topology). Assess the pattern in the named cells rather than assigning a single intensity to the whole section.
Strong nuclear-only staining, with no discernible membranous or cytoplasmic pattern.	A nuclear-only pattern does not match the reported IHC distribution or UniProt cell-membrane annotation (HPA: tissue IHC; UniProt P30872 subcellular location). Consider nonspecific staining or a detection artefact; compartment alone cannot establish which step caused it.
Prominent signal in a cell population listed as not detected, such as adipocytes or bone-marrow hematopoietic cells.	This conflicts with those cell-specific HPA IHC observations (HPA: adipocytes Not detected; hematopoietic cells Not detected). Consider antibody cross-reactivity or endogenous detection activity. The HPA result is a reference observation, not proof that every such cell must be negative in every section.
Uniform brown haze across tissue, stroma and empty areas, obscuring cell boundaries.	The distribution is difficult to reconcile with the reported membranous and cytoplasmic tissue pattern (HPA: tissue IHC). Diffuse chromogen can reflect background from staining or detection steps (general IHC practice); do not score it as cell-specific SSTR1 without a resolvable cellular pattern.
No discernible signal in duodenal, small-intestinal or stomach glandular cells.	These are listed as High in HPA IHC, so absence of signal warrants a technical check (HPA: glandular-cell staining High). It does not by itself prove SSTR1 is absent: HPA reports low consistency between antibody staining and RNA expression, and a single failed stain cannot identify its cause (HPA: IHC reliability).

💡Expected SSTR1 appearanceCall a convincing positive when glandular cells show discernible membranous staining with possible cytoplasmic signal in duodenum, small intestine or stomach, where HPA reports High staining; nuclear-only or field-wide haze is inconsistent with that reference pattern (HPA: tissue IHC; UniProt P30872 cell-membrane location).

How each factor affects the staining
Membrane topology and epitope access	SSTR1 has 7 transmembrane segments, with extracellular and cytoplasmic regions (UniProt P30872 topology). Antibody binding depends on its actual epitope and the staining conditions (general IHC practice); the supplied record does not identify the catalog antibody's epitope or establish a preferred retrieval condition.
Reported cell and tissue distribution	HPA lists High glandular-cell staining in duodenum, small intestine and stomach, but Not detected in specified cell types elsewhere, including adipocytes and lung alveolar cells (HPA: tissue IHC). Choose reference areas by the annotated cell type, since a tissue name alone does not define every cell's expected result.
Confidence in the IHC reference	The tissue IHC profile is Approved, while HPA explicitly notes low consistency between antibody staining and RNA expression (HPA: IHC reliability). HPA031506 is Approved for IHC; this status supports use of its observed pattern as a reference but does not independently validate every new antibody or staining run (HPA: antibody validation).
IF/ICC Q&A: should vesicles define the IHC result?	No. HPA calls the ICC-IF location vesicles uncertain, while its tissue IHC profile describes membranous and cytoplasmic expression (HPA: subcellular ICC-IF; HPA: tissue IHC). HPA003207 has Uncertain ICC status, so vesicular IF signal alone should not override the paraffin-section IHC interpretation (HPA: antibody validation).
Glycosylation and processing annotations	UniProt annotates 3 glycosylation sites at residues 4, 44 and 48, and one chain spanning residues 1–391 (UniProt P30872). These annotations do not specify the antibody epitope or demonstrate a target-specific effect of fixation, antigen retrieval or processing on IHC staining.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Expected glandular cells are blank while the control section also lacks signal.	A staining-run failure is possible; HPA reports High glandular-cell signal in duodenum, small intestine and stomach (HPA: tissue IHC). The paired absence does not identify which reagent or step failed.	Check section identity and staining-run controls, then review primary antibody, detection reagents and the documented IHC-P workflow (general IHC practice). Reassess glandular cells against the HPA reference pattern after the run is working.
Positive tissue stains, but the target section remains blank.	The target may contain fewer relevant cells, or its signal may be below the current assay's visibility; HPA levels apply to named cell populations (HPA: tissue IHC). Absence in one section is not a universal tissue-level negative.	Confirm that the intended cell population is present and intact, and compare it with the same-run positive control (general IHC practice). Record the cell type examined before interpreting the negative result.
The field is uniformly brown or boundaries are hard to resolve.	Diffuse background from chromogenic detection or nonspecific staining is possible (general IHC practice). It does not resemble the cell-associated membranous and cytoplasmic HPA pattern (HPA: tissue IHC).	Inspect a no-primary control and the counterstain; review blocking, washes and detection exposure in the established IHC-P workflow (general IHC practice). Score only signal that remains attributable to identifiable cells.
Signal is predominantly nuclear in several tissue regions.	This distribution conflicts with the reported membranous and cytoplasmic IHC profile and cell-membrane annotation (HPA: tissue IHC; UniProt P30872 subcellular location). The image alone cannot distinguish nonspecific binding from detection artefact.	Check a no-primary control and compare the same run with a known-positive gastrointestinal glandular-cell section (general IHC practice; HPA: glandular-cell staining High). Document the compartment before calling any staining positive.
Strong staining appears in adipocytes or lung alveolar cells.	HPA lists these specific cell populations as Not detected (HPA: adipocytes Not detected; alveolar cells Not detected). Cross-reactivity or endogenous detection activity is possible, although the discrepancy alone cannot prove either explanation.	Verify cell identification, inspect a no-primary control and compare with a same-run positive cell population (general IHC practice). Treat unresolved staining as discordant with the HPA reference rather than assigning SSTR1 positivity.
Cytoplasmic signal seems stronger than membrane staining.	HPA reports both membranous and cytoplasmic tissue staining, so cytoplasmic signal is not automatically discordant (HPA: tissue IHC). The uncertain vesicular ICC-IF result does not establish the precise compartment of an IHC signal (HPA: subcellular ICC-IF).	Check whether signal is confined to the expected cells and compare with same-run controls (general IHC practice). Describe the observed compartment and intensity separately; avoid interpreting diffuse field-wide staining as a cellular pattern.

Source: UniProt P30872 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing SSTR1 staining

PA1693 · IHCAnti-SSTR1 antibody, PA1693, IHC(P) IHC(P): Rat Intestine Tissue

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000139874-SSTR1/tissue/cerebral+cortex#imid_17407270

HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000139874-SSTR1/tissue/stomach+1#imid_17413430

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000139874-SSTR1/tissue/colon#imid_17413472

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000139874-SSTR1/tissue/liver#imid_17413465

HPA ICC-IF BJ [Human fibroblast] — SSTR1 (HPA003207)

HPA · ICC-IF BJ [Human fibroblast]Human Protein Atlas immunofluorescence, BJ [Human fibroblast], antibody HPA003207; green = SSTR1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for SSTR1 IHC & IF

🧪Run duodenum first and assess staining in glandular cells (HPA: High in duodenal glandular cells). Run adipose tissue as a negative comparator (HPA: Not detected in adipocytes); on the duodenal slide, use morphologically distinct nonglandular cells to assess background, without assuming they are SSTR1-negative (standard IHC practice).

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

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SSTR1 in BJ [Human fibroblast], HeLa, OE19, with annotated localisation: Vesicles (uncertain) (HPA subcellular).

Technical controls: Include a no-primary secondary-only control, a control matched to the primary antibody’s host species and clonality, and SSTR1 knockout material or an immunizing-peptide block if available (standard IHC controls). In duodenum, quench endogenous peroxidase and check for endogenous biotin if using biotin-based detection; assess autofluorescence if using IF (standard IHC/IF practice).

⚠️Feasibility: A target-specific fixation window and retrieval dependency are unreported in the supplied evidence; the selected rat-intestine IHC(P) caption also leaves the fixative unreported (PA1693 caption: fixative not stated). These data do not establish whether frozen sections or IF are easier than paraffin IHC (supplied evidence: no matched comparison). Intestinal autofluorescence can complicate IF interpretation (standard IF practice).

HPA tissue IHC evidence for SSTR1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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

Tissue	Cell type	Level	Evidence	Source
Duodenum	Glandular cells	High	Protein (IHC)	HPA →
Small intestine	Glandular cells	High	Protein (IHC)	HPA →
Stomach	Glandular cells	High	Protein (IHC)	HPA →
Testis	Elongated or late spermatids	High	Protein (IHC)	HPA →
Appendix	Glandular cells	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Caudate	Glial cells	Not detected	Protein (IHC)	HPA →
Cerebellum	Cells in granular layer	Not detected	Protein (IHC)	HPA →
Heart muscle	Cardiomyocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced SSTR1 IHC Tips

Troubleshoot SSTR1 staining in paraffin sections by checking retrieval, compartment, controls and cell-specific scoring before interpreting chromogenic signal.

How should I retrieve SSTR1 in paraffin sections when staining is weak?

Start with citrate buffer at pH 6.0, heated to 95–98 °C for 20 min (page retrieval specification). Allow sections to cool in buffer, then compare the same tissue and antibody lot across runs so a change in signal can be attributed to retrieval (standard IHC practice). If staining remains weak, test a different retrieval condition on adjacent sections as a fallback, with matched positive and negative controls (standard IHC practice). Score membrane and cytoplasmic staining separately, because SSTR1 is a membrane receptor and tissue IHC also reports cytoplasmic expression (UniProt P30872 subcellular location; HPA tissue IHC profile).

Could fixation explain variable SSTR1 staining between paraffin blocks?

SSTR1-specific fixation sensitivity is unknown from the supplied evidence, so record fixative, fixation duration and processing history for each block before comparing signal (supplied evidence; standard IHC practice). The PA1693 rat intestine image is labelled IHC(P), but its caption does not state the fixative (PA1693 tissue-IHC caption). Compare adjacent sections from blocks with documented processing using the same pH 6.0, 20 min retrieval and detection run (page retrieval specification; standard IHC practice). Check morphology and counterstaining alongside signal, and treat differences between undocumented blocks as inconclusive rather than assigning them to an SSTR1-specific fixation effect (standard IHC practice).

Should SSTR1 staining appear at the membrane or in the cytoplasm?

Expect a membrane component because SSTR1 is annotated at the cell membrane and contains 7 transmembrane segments (UniProt P30872 subcellular location and topology). Cytoplasmic signal can be evaluated separately because the tissue IHC profile reports membranous and cytoplasmic expression, while the subcellular IF entry lists vesicles with uncertain confidence (HPA tissue IHC profile; HPA subcellular summary). Inspect intact glandular cells in duodenum, small intestine or stomach, where high staining is reported, before judging faint compartments elsewhere (HPA tissue IHC positive cells). Record membrane and cytoplasmic scores independently; diffuse nuclear-only staining needs scrutiny because the supplied localisation evidence does not support a nuclear assignment (UniProt P30872 subcellular location; HPA tissue IHC profile).

How can epitope position change interpretation of SSTR1 staining?

Map the catalog antibody’s stated immunogen to SSTR1 before interpreting its staining, because the supplied record lists 0 isoforms but does not give this antibody’s epitope (UniProt P30872 isoforms; supplied antibody evidence). Residues 1–56 are extracellular, whereas residues 328–391 are cytoplasmic; intervening loops alternate across 7 membrane spans (UniProt P30872 topology). An intracellular epitope may need effective retrieval and access through the membrane in fixed sections, while accessibility of any epitope must be established experimentally (UniProt P30872 topology; standard IHC practice). Three annotated glycosylation sites at residues 4, 44 and 48 provide context for an N-terminal epitope, but do not establish an antibody-specific staining effect (UniProt P30872 glycosylation).

How should I check SSTR1 localisation with multiplex IF?

Use IF as a separate validation experiment and pair SSTR1 with a marker identifying the glandular cell population being examined, since glandular cells show high tissue IHC staining in duodenum, small intestine and stomach (HPA tissue IHC positive cells; standard IF practice). Choose spectrally separated fluorophores and a channel with low tissue autofluorescence, then inspect single-stain controls before interpreting overlap (standard IF practice). Match permeabilisation to the antibody’s stated epitope: cytoplasmic loops or the 328–391 tail require intracellular access, while an extracellular epitope calls for an accessibility check (UniProt P30872 topology; standard IF practice). Compare membrane and punctate signal separately because tissue IHC reports membranous and cytoplasmic expression, while the subcellular IF localisation to vesicles is uncertain (HPA tissue IHC profile; HPA subcellular summary).

What controls help distinguish SSTR1 signal from chromogenic background?

Run a no-primary control alongside the IHC-validated antibody and inspect both with the same chromogen exposure and counterstain (standard IHC practice). Quench endogenous peroxidase before DAB development when using peroxidase detection, and examine whether residual colour follows tissue structures independently of primary antibody (standard chromogenic IHC practice). Compare antibody-treated and control sections in glandular cells of duodenum, small intestine or stomach, where high staining is reported, and in a matched area with little reported staining (HPA tissue IHC positive cells; standard IHC practice). Reduce detection intensity or adjust blocking only after checking controls, so changes in background are not mistaken for improved SSTR1 specificity (standard IHC practice).

How should I quantify SSTR1 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and compartment before scoring, because SSTR1 is membrane annotated while tissue IHC reports both membranous and cytoplasmic signal (UniProt P30872 subcellular location; HPA tissue IHC profile). For a selected cell population, report percentage positive and an H-score using intensity grades 0–3, calculated as the sum of each grade multiplied by its percentage of cells (standard IHC scoring practice). If counting discrete positive cells, report density per mm² of viable tissue and exclude folds or necrotic regions (standard IHC scoring practice). Normalise comparisons to the same defined cell population, viable area, staining run and scoring threshold; analyse membrane and cytoplasmic results separately (standard IHC scoring practice).

When is SSTR1 staining convincing rather than an artefact?

Give greater weight to reproducible staining in the expected cell and compartment: high glandular-cell staining is reported in duodenum, small intestine and stomach, and SSTR1 is membrane annotated (HPA tissue IHC positive cells; UniProt P30872 subcellular location). Assess cytoplasmic signal separately because the tissue IHC profile includes it, although that profile has low consistency with RNA expression (HPA tissue IHC profile and reliability description). Treat nuclear-only colour, section-edge accentuation, necrotic deposits and signal persisting without primary antibody as reasons to investigate artefact or detection background (UniProt P30872 subcellular location; standard IHC practice). Recheck a questionable pattern in adjacent sections with matched controls before assigning biological meaning to its intensity or distribution (standard IHC practice).

Boster reagents

Best SSTR1 / Somatostatin receptor type 1 IHC Antibodies

The catalog includes a rat intestine paraffin-section IHC image (PA1693 image caption) and a human-reactive IF/ICC antibody listing (M04717 catalog applications/reactivity).

Real IHC data Anti-SSTR1 antibody, PA1693, IHC(P) IHC(P): Rat Intestine Tissue

Anti-Somatostatin Receptor 1/SSTR1 Antibody ®

Cat # PA1693

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PA1693 will render with its own rat intestine paraffin-section IHC image (PA1693 image caption). It lists IHC reactivity for human, mouse and rat (PA1693 catalog applications/reactivity).

Which to pick: Choose PA1693 for tissue IHC or work across human, mouse and rat: its IHC image shows rat intestine in a paraffin section (PA1693 image caption), and its listed IHC dilution is 0.5–1 μg/ml (PA1693 datasheet). The fixative for that image is unreported (PA1693 image caption). For human IF/ICC, M04717 is a rabbit monoclonal with IF/ICC listed at 1:50 (M04717 catalog applications/reactivity/clone and IF dilution).

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

References

UniProt Consortium. UniProt entry P30872 (SSR1_HUMAN, Somatostatin receptor type 1).
Human Protein Atlas. SSTR1 tissue IHC expression (reliability: Approved).
Human Protein Atlas. SSTR1 subcellular location (ICC-IF): Localized to vesicles..
Human Protein Atlas. SSTR1 antibody validation summary (2 antibodies).
Correlation of Somatostatin Receptor 1-5 Expression, [(68)Ga]Ga-DOTANOC, [(18)F]F-FDG PET/CT and Clinical Outcome in a Prospective Cohort of Pancreatic Neuroendocrine Neoplasms. Cancers 2021 — PMC8750461.
High Expression of Somatostatin Receptors 2A, 3, and 5 in Corticotroph Pituitary Adenoma. International journal of endocrinology 2018 — PMC6304820.
The immunohistochemical expression of SSTR2A is an independent prognostic factor in meningioma. Neurosurgical review 2022 — PMC9349155.
Somatostatin receptors in fibrotic myocardium. PloS one 2024 — PMC11262693.
PubMed PMID:1346068 — UniProt-cited evidence.
PubMed PMID:15489334 — UniProt-cited evidence.
PubMed PMID:10734105 — UniProt-cited evidence.