PTGS1 / Prostaglandin G/H synthase 1 · IHC design guide

Design Immunohistochemistry for PTGS1

Plan PTGS1 chromogenic IHC in paraffin sections with the catalog antibody’s documented 2 µg/mL starting concentration (datasheet PB9002). Use the reported tissue staining to select control cell populations and assess 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 PTGS1 (IHC for PTGS1): expected localisation Cytoplasmic tissue staining (HPA tissue IHC), antibody PB9002, validated IHC image, and IHC protocol steps — Printable **PTGS1** IHC protocol sheet — expected localisation Cytoplasmic tissue staining (HPA tissue IHC), antibody PB9002, controls and protocol steps. Open the full PTGS1 IHC guide →

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PTGS1 Immunohistochemistry Experimental Design Guide

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

Must know before staining

	Expected localisation	Cytoplasmic tissue staining (HPA tissue IHC)
	Staining pattern	Variable cytoplasmic staining; high in squamous epithelia (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet PB9002)
	Positive control ⓘ	Appendix+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 paraffin sections. (standard IHC practice; not target-specific)
	Caveat	Stromal cell staining may complicate epithelial scoring (HPA tissue IHC)
	Regulation	Expression regulation is not annotated (UniProt)
	Isoform / epitope	6 isoforms; effects on antibody epitopes are unspecified (UniProt)

Section 1

Recommended PTGS1 IHC & IF Protocols

Compare the catalog antibody’s IHC-P protocol (datasheet PB9002) with three published PTGS1 IHC protocols (PMC13338899; PMC12234924; PMC3896710).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet PB9002)
Fixation	Image fixative and duration unreported (datasheet PB9002); 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 PB9002); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet PB9002)
Primary antibody	Rabbit anti-PTGS1, 2-5μg/ml (datasheet PB9002)
Primary incubation	Overnight at 4 °C (datasheet PB9002)
Detection	HRP-conjugated secondary, DAB chromogen (datasheet PB9002)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	PTGS1-positive staining in endocrine cells of appendix (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression at variable levels in several tissues, high expression in squamous epithelia, megakaryocytes, fallopian tube, brain and subsets of cells in tissue stroma. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet PB9002); the prostate cancer protocol also reports EDTA at pH 8.0 (PMC12234924).

Section 2

What Is the Expected PTGS1 Staining Pattern?

PTGS1 is associated with endoplasmic reticulum and microsome membranes, despite having no transmembrane segment (UniProt P23219 localization and topology). In paraffin-section IHC, expect cytoplasmic staining in selected cell populations, including fallopian tube glandular cells, skin granular-layer cells and intestinal endocrine cells (HPA: tissue IHC). HPA rates the tissue profile Enhanced, with medium consistency between antibody staining and RNA expression and support from paired antibodies (HPA: tissue IHC reliability).

What am I looking at on my slide?
Cytoplasmic staining in fallopian tube glandular cells or skin granular-layer cells.	This matches cell populations scored High by HPA (HPA: fallopian tube and skin tissue IHC). Score the named cells separately from adjacent cells; HPA's High designation applies to those populations, not every cell in the section (HPA: tissue IHC).
Strong nuclear-only staining, without a convincing cytoplasmic component.	This conflicts with the cytoplasmic tissue profile (HPA: tissue IHC) and the endoplasmic reticulum and microsome membrane localization (UniProt P23219 localization). Treat it as suspect until a known-positive cell population shows the expected pattern and controls exclude detection artefact (general IHC practice).
Strong staining in adipocytes or bronchial respiratory epithelial cells.	HPA reports PTGS1 as Not detected in those specific cell populations (HPA: adipose tissue and bronchus tissue IHC). Check whether staining persists without primary antibody; persistent signal suggests endogenous detection activity, while primary-dependent signal warrants an antibody-specificity review (general IHC practice).
Uniform color across cells, stroma and empty areas.	A field-wide deposit does not reproduce HPA's variable, cell-selective cytoplasmic profile (HPA: tissue IHC). Consider nonspecific background or detection-reagent activity; compare no-primary controls and inspect whether the deposit respects cell boundaries (general IHC practice).
No staining in a section containing fallopian tube glandular cells.	Those cells are scored High by HPA (HPA: fallopian tube tissue IHC), so their absence of signal makes the run inconclusive for a negative result elsewhere. Check tissue preservation, antibody and detection performance using the assay's validated controls (general IHC practice).

💡Expected PTGS1 appearanceCall positive when selected High-scoring cells show convincing cytoplasmic signal—such as fallopian tube glandular cells or skin granular-layer cells (HPA: tissue IHC); nuclear-only or indiscriminate field-wide color is suspect against that profile (HPA: tissue IHC; general IHC practice).

How each factor affects the staining
Cell population selected for comparison	HPA scores endocrine cells in appendix, colon, duodenum and rectum as High, but stomach glandular cells as Low (HPA: tissue IHC). Compare like cell types when judging intensity; a weak stomach result cannot be treated as failure solely because an intestinal endocrine population stains strongly.
Compartment and optical resolution	UniProt places PTGS1 at endoplasmic reticulum and microsome membranes without a transmembrane segment (UniProt P23219 localization and topology). HPA describes tissue staining as cytoplasmic (HPA: tissue IHC); chromogenic sections may establish a cytoplasmic pattern without resolving the specific membrane system (general IHC practice).
Antibody validation in IHC	HPA lists Enhanced IHC validation for HPA002834 and CAB020315 (HPA: antibody validation). Its tissue profile also has medium consistency with RNA and support from paired antibodies (HPA: tissue IHC reliability). These findings support interpretation of the reported pattern, while each assay still needs appropriate controls (general IHC practice).
IF/ICC expected localization?	HPA reports Golgi apparatus and vesicles as uncertain ICC-IF locations, and lists HPA002834 ICC validation as Uncertain (HPA: subcellular and antibody validation). Treat puncta in IF/ICC as provisional; do not require that appearance to call a chromogenic tissue IHC result positive (HPA: tissue IHC; general assay interpretation).
Processing and sequence diversity	UniProt lists a signal peptide at residues 1–23, a mature chain at 24–599, six isoforms and glycosylation sites at residues 67, 103 and 143 (UniProt P23219 processing, isoforms and glycosylation). Without an antibody epitope map, these facts do not establish which forms the assay detects or predict a retrieval response.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Known-positive glandular cells have no visible signal.	A failed run or unsuitable assay conditions are possible; fallopian tube glandular cells are High in HPA tissue IHC (HPA: fallopian tube).	Review the positive control, antibody and detection steps together before scoring other populations negative (general IHC practice). Do not infer PTGS1-specific fixation sensitivity from this result.
Adipocytes appear as strongly positive as the intended cells.	HPA scores adipocytes Not detected (HPA: adipose tissue IHC); primary-independent signal or cross-reactivity may explain the discrepancy (general IHC practice).	Compare a no-primary control, then assess whether signal tracks the antibody; verify cell identity and repeat with an independently validated antibody if needed (general IHC practice; HPA: paired-antibody support).
Nuclei dominate while cytoplasm remains unstained.	Nuclear-only signal conflicts with HPA's cytoplasmic tissue profile (HPA: tissue IHC) and UniProt's membrane-associated localization (UniProt P23219 localization).	Inspect counterstain and no-primary controls, then reassess the known-positive cytoplasmic population before accepting a nuclear result (general IHC practice).
Every compartment carries diffuse chromogen.	The distribution does not match HPA's variable, cell-selective tissue staining (HPA: tissue IHC); nonspecific binding or endogenous detection activity is possible (general IHC practice).	Check no-primary controls and the blocking and detection workflow; score only staining that remains cell-localized above background (general IHC practice).
Stomach glandular cells look faint beside intestinal endocrine cells.	HPA scores stomach glandular cells Low and intestinal endocrine cells High (HPA: tissue IHC).	Judge each population against its own reported level and a run control; do not increase exposure or chromogen development solely to equalize these cell types (HPA: tissue IHC; general IHC practice).
IF/ICC puncta seem inconsistent with the IHC slide.	Golgi and vesicle ICC-IF assignments are uncertain (HPA: subcellular), whereas tissue IHC reports cytoplasmic staining (HPA: tissue IHC).	Interpret the assays separately; use the cell-selective cytoplasmic IHC pattern for this paraffin-section readout and treat the IF/ICC localization as provisional (HPA: tissue IHC and subcellular).

Source: UniProt P23219 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing PTGS1 staining

IHC analysis of COX1/Cyclooxygenase 1/PTGS1 using anti-COX1/Cyclooxygenase 1/PTGS1 antibody (PB9002). COX1/Cyclooxygenase 1/PTGS1 was detected in a paraffin-embedded section of human breast cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml rabbit anti-COX1/Cyclooxygenase 1/PTGS1 Antibody (PB9002) 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.

PB9002 · IHCIHC analysis of COX1/Cyclooxygenase 1/PTGS1 using anti-COX1/Cyclooxygenase 1/PTGS1 antibody (PB9002). COX1/Cyclooxygenase 1/PTGS1 was detect

M00811 · IHCImmunohistochemical analysis of paraffin-embedded human uterus, using COX1 Antibody.

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000095303-PTGS1/tissue/cerebral+cortex#imid_973504

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000095303-PTGS1/tissue/colon#imid_973422

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000095303-PTGS1/tissue/liver#imid_973431

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000095303-PTGS1/tissue/kidney#imid_973416

HPA ICC-IF BJ [Human fibroblast] — PTGS1 (HPA002834)

HPA · ICC-IF BJ [Human fibroblast]Human Protein Atlas immunofluorescence, BJ [Human fibroblast], antibody HPA002834; green = PTGS1, blue = nucleus, red = microtubules.

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

Sample controls for PTGS1 IHC & IF

🧪Run appendix first and look for PTGS1 staining in endocrine cells (HPA: High in appendix endocrine cells). Use adipose tissue adipocytes as the negative comparison (HPA: Not detected in adipocytes); on the appendix slide, compare endocrine cells with neighboring non-endocrine cells and treat those cells as an internal negative only if they lack specific staining.

Positive control tissue: Appendix (Endocrine cells, HPA High)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PTGS1 in BJ [Human fibroblast], U-251MG, U2OS, ASC52telo, RPTEC/TERT1, with annotated localisation: Golgi apparatus (uncertain), Vesicles (uncertain) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only control; a concentration-matched rabbit IgG isotype control (selected PB9002 caption: rabbit primary); and, if available, a PTGS1 knockout specimen or peptide-blocked primary as a biological specificity control. For chromogenic appendix IHC, quench endogenous peroxidase and check the no-primary slide for background DAB signal (standard IHC practice).

⚠️Feasibility: A target-specific fixation window or fixation effect is unreported in the supplied evidence, and the fixative used for the selected PB9002 paraffin-section image is unreported (selected PB9002 caption). Heat retrieval in EDTA at pH 8.0 is a documented starting condition for this antibody, though the caption shows breast cancer tissue rather than appendix (selected PB9002 caption); the evidence does not establish that frozen sections or IF are easier. In appendix, endogenous peroxidase can produce chromogenic background, so interpret staining against the quenched no-primary control (standard IHC practice).

HPA tissue IHC evidence for PTGS1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Paired antibodies with high similarity support the protein profile.). 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
Appendix	Endocrine cells	High	Protein (IHC)	HPA →
Colon	Endocrine cells	High	Protein (IHC)	HPA →
Duodenum	Endocrine cells	High	Protein (IHC)	HPA →
Endometrium	Glandular cells	High	Protein (IHC)	HPA →
Fallopian tube	Glandular cells	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 →
Bronchus	Respiratory epithelial cells	Not detected	Protein (IHC)	HPA →
Heart muscle	Cardiomyocytes	Not detected	Protein (IHC)	HPA →
Nasopharynx	Respiratory epithelial cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced PTGS1 IHC Tips

Troubleshoot PTGS1 staining in paraffin sections by checking retrieval, cell identity and intracellular pattern before comparing signal intensity across samples.

How should I adjust retrieval when PTGS1 staining is weak in paraffin sections?

Start with heat-mediated retrieval in EDTA at pH 8.0 for the catalog antibody (datasheet PB9002). Its paraffin-section image used that retrieval, followed by 2 μg/ml primary antibody overnight at 4°C (caption PB9002). If staining is weak, compare retrieval heating and cooling conditions on adjacent sections while holding antibody concentration, detection and development constant; record tissue integrity as well as signal. Include a section with an expected positive cell population, such as fallopian-tube glandular cells (HPA: High in fallopian-tube glandular cells). Treat any alternative buffer or pH as an optimization experiment requiring its own controls.

Could fixation explain variable PTGS1 staining between paraffin blocks?

The selected paraffin-section caption does not report a fixative, so target-specific fixation sensitivity is unknown (caption PB9002: fixative not stated). Compare blocks only after documenting fixation type, duration, tissue thickness and processing, since each can alter antigen accessibility in routine IHC. On adjacent sections, keep EDTA retrieval at pH 8.0 and the primary at 2 μg/ml overnight at 4°C while checking whether the difference persists (caption PB9002). Use a consistently processed positive control and a no-primary control in each run to separate staining variability from tissue-dependent signal. Do not infer fixation tolerance from expression patterns.

Which intracellular PTGS1 pattern should count as convincing IHC staining?

Score staining within the cytoplasm, with attention to a perinuclear or fine intracellular distribution compatible with endoplasmic-reticulum and microsome membranes (HPA: cytoplasmic tissue expression; UniProt P23219: ER and microsome membranes). PTGS1 has no transmembrane segment, so a crisp cell-surface outline alone warrants scrutiny (UniProt P23219 topology). Golgi and vesicle assignments from cell imaging are uncertain and should not define the tissue-IHC acceptance criterion by themselves (HPA subcellular: uncertain Golgi apparatus and vesicles). Compare stained cells with neighboring unstained cells and the counterstain, then check a no-primary section for pigment, precipitate or endogenous peroxidase. Record nuclear-only staining separately for review rather than including it automatically.

Can this IHC result distinguish PTGS1 isoforms or reveal epitope masking?

PTGS1 has 6 annotated isoforms, but the supplied IHC caption gives no epitope sequence or isoform-specific validation (UniProt P23219 isoforms; caption PB9002). The precursor includes a signal peptide at residues 1–23, an EGF-like domain at 31–69 and glycosylation sites at 67, 103 and 143 (UniProt P23219 processing and features). Those features justify checking the antibody's documented epitope before interpreting absent staining as an absent isoform; they do not establish which feature masks this antibody. Compare retrieval conditions on adjacent sections using the documented EDTA pH 8.0 condition as the reference (datasheet PB9002). Report staining as PTGS1 immunoreactivity unless epitope and isoform specificity are independently demonstrated.

How can IF help check a disputed PTGS1 cell assignment?

Use IF as a complementary cell-identification experiment while interpreting this page's primary result as chromogenic paraffin-section IHC. Multiplex PTGS1 with a marker for the proposed cell type, such as CD31 when assessing endothelial cells; lung endothelial cells show high PTGS1 in the tissue profile (HPA: High in lung endothelial cells). Choose fluorophores after inspecting tissue autofluorescence in unstained sections, and include single-label controls to set channel separation. Because PTGS1 associates with ER and microsome membranes but the antibody epitope's membrane-facing side is unspecified, optimize post-fixation permeabilisation empirically rather than assuming antibody access (UniProt P23219 localisation and topology; caption PB9002: epitope not specified). Confirm the cell assignment against morphology on the chromogenic section.

How do I reduce diffuse or vascular background in PTGS1 chromogenic IHC?

Run a no-primary section to identify signal from the detection system, and include a peroxidase block before HRP and DAB development as routine chromogenic-IHC practice. The catalog example used 10% goat serum block, 2 μg/ml primary overnight at 4°C, and an HRP-based DAB readout (caption PB9002). If diffuse staining persists, compare a lower primary concentration or shorter DAB development on adjacent sections while holding retrieval at EDTA pH 8.0 (datasheet PB9002). Check whether apparent vascular signal resolves to cells: endothelial staining can be genuine in lung (HPA: High in lung endothelial cells). Exclude precipitate, section edges and damaged tissue before assigning positivity.

What should I score when comparing PTGS1 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and intracellular staining criterion before scoring, because PTGS1 levels vary across tissues and cell types (HPA tissue IHC profile). Within a prespecified region, report the percentage of positive target cells and an H-score based on intensity categories, or positive-cell density per mm² when the number of target cells changes. Normalize cell-based results to all evaluable cells of the same type, and area-based results to viable tissue area; exclude folds, necrosis and edges by the same rule in every section. Keep retrieval at EDTA pH 8.0 and detection settings consistent across the comparison (datasheet PB9002). Record control performance alongside scores.

When should an apparent PTGS1-positive cell be treated as artefact?

Favor cytoplasmic staining in an anatomically credible cell population: the tissue profile reports high signal in fallopian-tube glandular cells and lung endothelial cells (HPA tissue IHC), while PTGS1 is associated with ER and microsome membranes (UniProt P23219 localisation). Question isolated nuclear-only or sharp surface-only signal, as well as staining restricted to section edges, necrotic regions or deposits. Check a no-primary section and peroxidase-blocked control when DAB signal may reflect endogenous enzyme or detection background; HRP and DAB were used in the selected paraffin example (caption PB9002). A matched positive control and repeat section help distinguish reproducible cell-associated staining from processing artefact. Interpret intensity in the named cell type, since the profile is variable across tissues (HPA tissue IHC).

Boster reagents

Best PTGS1 / Prostaglandin G/H synthase 1 IHC Antibodies

Both antibodies have human paraffin-section IHC images; PB9002 also has a mouse colon IHC image, while M00811 lists IF/ICC for human, mouse, and rat (catalog image captions; applications/reactivity).

Real IHC data

Anti-COX1/Cyclooxygenase 1/PTGS1 Antibody ®

Cat # PB9002

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Real IHC data Immunohistochemical analysis of paraffin-embedded human uterus, using COX1 Antibody.

Anti-COX1 PTGS1 Rabbit Monoclonal Antibody

Cat # M00811

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PB9002 has IHC images from paraffin-embedded human breast cancer, colonic adenoma, and lung cancer tissue, plus mouse colon (PB9002 IHC captions). M00811 has a paraffin-embedded human uterus IHC image and lists human, mouse, and rat reactivity and IF/ICC use; no IF image is supplied (M00811 IHC caption; catalog applications/reactivity).

Which to pick: For tissue IHC, choose PB9002 when its documented paraffin-section conditions are useful: EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody overnight at 4°C (PB9002 IHC captions). For IF/ICC, choose the rabbit monoclonal M00811 because IF/ICC is listed at 1:50; its supplied figure documents only paraffin-section IHC (M00811 catalog applications/dilution; IHC caption). Both list human, mouse, and rat reactivity, but PB9002 also has a mouse tissue IHC image; neither IHC caption reports the fixative (catalog reactivity; PB9002 and M00811 IHC captions).

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

References

UniProt Consortium. UniProt entry P23219 (PGH1_HUMAN, Prostaglandin G/H synthase 1).
Human Protein Atlas. PTGS1 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. PTGS1 subcellular location (ICC-IF): Localized to the Golgi apparatus and vesicles..
Human Protein Atlas. PTGS1 antibody validation summary (2 antibodies).
Blautia-PTGS1 co-occurrence in prolactinomas: potential implications for tumor microenvironment and invasiveness. Journal of the Endocrine Society 2026 — PMC13338899.
Aspirin alters molecular crosstalk between prostaglandin, apoptosis, and invasion pathways in colorectal cancer. BMC cancer 2026 — PMC13227888.
Nicotine and tar-multiple targets synergize to alter the immune micro-environment to induce prostate cancer. Discover oncology 2025 — PMC12234924.
Tumour angiogenesis in Epstein-Barr virus-associated post-transplant smooth muscle tumours. Clinical sarcoma research 2014 — PMC3896710.
PubMed PMID:2512924 — UniProt-cited evidence.
PubMed PMID:1907252 — UniProt-cited evidence.
PubMed PMID:1734857 — UniProt-cited evidence.