This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
TACR1 / Substance-P receptor · IHC design guide
Design Immunohistochemistry for TACR1
This guide covers paraffin section IHC for TACR1 using the IHC-validated M01006 antibody at 1:50 (datasheet M01006). Assess cytoplasmic staining in squamous epithelial cells (HPA tissue IHC), while considering receptor movement to early endosomes after substance P binding (UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
TACR1 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 | Epithelial cytoplasm (HPA tissue IHC) | |
| Staining pattern | Squamous epithelial cells: cytoplasmic staining (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M01006) | |
| Positive control | Bronchus+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 | Substance P can shift receptor into early endosomes (UniProt) | |
| Regulation | No expression regulator annotated (UniProt) | |
| Isoform / epitope | 2 isoforms; map extracellular versus cytoplasmic epitopes (UniProt) |
Section 1
Recommended TACR1 IHC & IF Protocols
The catalog antibody uses heat-mediated EDTA pH 8.0 retrieval (datasheet: M01006). The published rat spinal cord IHC protocol uses citric acid pH 6.0 and chromogenic detection (PMC10954158).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet M01006) |
| Fixation | Image fixative and duration unreported (datasheet M01006); 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 M01006); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M01006) |
| Primary antibody | Rabbit monoclonal (clone AFBH-20) anti-TACR1, 1:50 (datasheet M01006) |
| Primary incubation | Overnight at 4 °C (datasheet M01006) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet M01006) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | TACR1-positive staining in respiratory epithelial cells of bronchus (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in squamous epithelia. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 for the catalog antibody (datasheet: M01006); compare citric acid pH 6.0 when adapting the published protocol (PMC10954158).
Section 2
What Is the Expected TACR1 Staining Pattern?
TACR1 is a seven-pass receptor at the cell membrane that can move to early endosomes after substance P binding (UniProt P25103 topology and subcellular location). In paraffin IHC, expect staining in squamous epithelial cells of cervix, esophagus and vagina, and in skin keratinocytes; HPA reports medium staining in these cells (HPA tissue IHC). Its tissue profile has Enhanced reliability, with medium agreement between staining and RNA and external verification pending (HPA tissue IHC).
| Membrane-associated staining, with some cytoplasmic signal, in the expected epithelial cells. | This fits the membrane location and possible endosomal internalization of TACR1 (UniProt P25103 subcellular location). HPA describes cytoplasmic staining in squamous epithelia and medium staining in cervix, esophagus, vagina and skin keratinocytes (HPA tissue IHC). Score the relevant cells and compartments rather than requiring a continuous membrane outline. |
| Predominantly nuclear staining, without convincing membrane-associated or epithelial cytoplasmic staining. | A nuclear pattern is outside the supplied TACR1 localization evidence: UniProt places the receptor at the membrane and early endosomes, while HPA describes cytoplasmic staining in squamous epithelia (UniProt P25103 subcellular location; HPA tissue IHC). Treat this pattern as suspect and compare it with a known-positive section and the detection control before assigning TACR1 positivity (general IHC practice). |
| Staining concentrates in a cell population listed as not detected by HPA. | For example, HPA reports TACR1 as not detected in adipocytes of adipose tissue and hematopoietic cells of bone marrow (HPA tissue IHC). Unexpected staining raises cross-reactivity or endogenous detection activity as possibilities (general IHC practice). Check the named cell population, since those HPA observations do not declare every cell in either tissue negative. |
| Diffuse color covers cells and surrounding tissue without a clear cellular pattern. | This is difficult to interpret as TACR1 when the expected evidence points to membrane-associated and epithelial cytoplasmic localization (UniProt P25103 subcellular location; HPA tissue IHC). Review background on a section processed without primary antibody, then optimize the chromogenic workflow if background persists (general IHC practice). |
| No staining appears in the expected epithelial cells of a positive reference section. | HPA reports medium staining in cervix, esophagus and vagina squamous epithelial cells, and skin keratinocytes (HPA tissue IHC). A blank reference section makes a negative result in the experimental section inconclusive. Check antibody and detection performance, tissue preservation and the assay's routine retrieval conditions (general IHC practice); the supplied sources do not establish TACR1-specific fixation sensitivity. |
💡Expected TACR1 appearanceCall a paraffin IHC result positive when the expected epithelial cells show interpretable membrane-associated and/or cytoplasmic staining, around HPA's medium level; isolated nuclear or diffuse background color is suspect (UniProt P25103 subcellular location; HPA tissue IHC; general IHC practice).
| Seven-pass topology and epitope access | UniProt maps extracellular and cytoplasmic regions around seven transmembrane segments (UniProt P25103 topology). If an antibody's epitope is known, its position can guide interpretation of accessibility after section processing; no epitope position or TACR1-specific retrieval requirement is supplied here. Follow the validated IHC procedure for the antibody used (general IHC practice). |
| Receptor trafficking | Substance P binding can move TACR1 from the cell surface to early endosomes, followed by recycling (UniProt P25103 subcellular location). Thus, some intracellular signal can be biologically plausible. That mechanism alone cannot prove that cytoplasmic chromogen in an individual section is specific; compare its distribution with the HPA epithelial pattern and controls. |
| Tissue-pattern confidence | HPA labels the tissue IHC profile Enhanced, yet describes only medium consistency with RNA and says external verification is pending (HPA tissue IHC). Use its named cell types and staining levels as reference observations, while keeping an independent positive reference and detection control in the assay (general IHC practice). |
| Isoforms and glycosylation | UniProt records two TACR1 isoforms and glycosylation sites at residues 14 and 18 (UniProt P25103 isoforms and glycosylation). The supplied record gives no antibody epitope or isoform selectivity. Do not assign different staining patterns to isoforms or infer a retrieval effect from the glycosylation sites. |
| IF/ICC Q&A: what location is supported? | HPA supports plasma-membrane localization in ICC-IF; its centrosome and basal-body assignments are uncertain (HPA subcellular ICC-IF). UniProt also places TACR1 in early endosomes after signaling (UniProt P25103 subcellular location). Use the separate IF/ICC guide for that application; these observations supply no IF protocol or basis for treating puncta as definitive endosomes. |
| Situation | Likely cause | Next action |
|---|---|---|
| The positive reference section is blank. | The assay may have failed, or the sampled reference may lack the expected cells; HPA's positive observations refer to specified epithelial populations (HPA tissue IHC). | Confirm those cells are present, then check primary-antibody use, detection reagents and routine IHC retrieval settings against the validated procedure (general IHC practice). Do not infer TACR1-specific fixation failure from this result. |
| Nuclear color dominates the section. | Nuclear localization is unsupported by UniProt's membrane and early-endosome annotation and HPA's squamous-epithelial cytoplasmic profile (UniProt P25103 subcellular location; HPA tissue IHC). | Compare a known-positive section and a no-primary control; review counterstain and chromogen interpretation before scoring (general IHC practice). Record the nuclear result as unresolved if the controls cannot explain it. |
| Unexpected cells stain strongly. | Cross-reactivity or endogenous detection activity is possible (general IHC practice). HPA's not-detected calls apply to named cells, such as adipocytes in adipose tissue, rather than whole tissues (HPA tissue IHC). | Identify the stained cell type, run a no-primary control, and check endogenous-enzyme blocking for chromogenic detection (general IHC practice). Compare only the same cell population with HPA. |
| Color is widespread and obscures cell boundaries. | Diffuse background can reflect nonspecific binding or detection background (general IHC practice); it does not resolve into the expected epithelial pattern (HPA tissue IHC). | Inspect the no-primary control, review blocking and washing, and adjust antibody concentration or detection conditions using the validated IHC procedure (general IHC practice). Reassess only after cell boundaries are readable. |
| Staining is cytoplasmic but lacks a crisp membrane rim. | HPA describes cytoplasmic expression in squamous epithelia; UniProt permits early-endosomal localization after substance P signaling (HPA tissue IHC; UniProt P25103 subcellular location). Neither source establishes the cause of cytoplasmic signal in this section. | Check whether staining is confined to the expected epithelial cells and exceeds control background (HPA tissue IHC; general IHC practice). Report the observed compartment without calling it endosomal unless separately demonstrated. |
| An IF/ICC image shows centrosomal or basal-body spots. | HPA marks those locations uncertain while supporting the plasma membrane in ICC-IF (HPA subcellular ICC-IF). | Treat the spots as unconfirmed TACR1 localization and consult the separate IF/ICC guide. Do not use those uncertain locations to score a paraffin IHC section positive (HPA subcellular ICC-IF). |
Experiment evidence
IHC & IF images showing TACR1 staining
M01006 · IHCIHC analysis of Neurokinin 1 Receptor using anti-Neurokinin 1 Receptor antibody (M01006). Neurokinin 1 Receptor was detected in a paraffin-e
M01006 · IHCIHC analysis of Neurokinin 1 Receptor using anti-Neurokinin 1 Receptor antibody (M01006). Neurokinin 1 Receptor was detected in a paraffin-e
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000115353-TACR1/tissue/cerebral+cortex#imid_20104757
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000115353-TACR1/tissue/colon#imid_20104235
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000115353-TACR1/tissue/liver#imid_20104252
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000115353-TACR1/tissue/kidney#imid_20104237
HPA · ICC-IF EFO-21Human Protein Atlas immunofluorescence, EFO-21, antibody HPA055565; green = TACR1, blue = nucleus, red = microtubules.
HPA · ICC-IF EFO-21Human Protein Atlas immunofluorescence, EFO-21, antibody HPA055565; green = TACR1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for TACR1 IHC & IF
🧪Run bronchus first and assess respiratory epithelial cells for TACR1 staining (HPA: Medium in bronchus respiratory epithelial cells). Use adipose tissue as the negative tissue and assess adipocytes, where TACR1 was not detected (HPA: Not detected in adipocytes); cells within the bronchus section that lack specific staining should remain free of convincing membrane signal (UniProt P25103 subcellular location).
Positive control tissue: Bronchus (Respiratory epithelial cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show TACR1 in EFO-21, SuSa, U2OS, ASC52telo, RPTEC/TERT1, hTERT-RPE1 (serum starved), with annotated localisation: Plasma membrane (supported), Centrosome (uncertain), Basal body (uncertain) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and concentration-matched nonimmune rabbit IgG controls, matching the catalog antibody’s rabbit host (selected M01006 caption: rabbit primary antibody), plus TACR1 knockout material as a biological negative where available (standard IHC practice). For chromogenic detection, block endogenous peroxidase and check background in the bronchus section (selected M01006 caption: peroxidase secondary and DAB; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact M01006 tissue-IHC caption does not state a fixative (selected M01006 caption: fixative not stated). The paraffin-section example used heat retrieval in EDTA, pH 8.0, so that condition is a practical starting point; retrieval dependence and whether frozen sections or IF are easier remain unreported (selected M01006 caption: heat-mediated EDTA retrieval; HPA: tissue IHC and ICC-IF evidence). In bronchus, distinguish epithelial staining from background associated with mucus or inflammatory cells during scoring (standard IHC practice).
HPA tissue IHC evidence for TACR1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — 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 |
|---|---|---|---|---|
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Cervix | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Prostate | Glandular cells | Medium | Protein (IHC) | HPA → |
| Skin | Keratinocytes | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced TACR1 IHC Tips
Troubleshoot TACR1 staining in paraffin sections by checking retrieval, compartment, cell type and controls before comparing signal intensity.
Which retrieval condition should I start with for TACR1 in paraffin sections?
Start with heat-mediated retrieval in EDTA buffer at pH 8.0 for the catalog antibody (datasheet M01006). The selected paraffin-section image used that condition, followed by 10% goat serum blocking and antibody incubation at 1:50 overnight at 4°C (M01006 tissue-IHC caption). If staining is weak, check that sections received consistent heating and cooling before changing antibody concentration (standard IHC practice). Compare retrieval changes on adjacent sections using the same detection and exposure conditions, because tissue damage or diffuse background can make an apparent gain misleading (standard IHC practice).
How should I troubleshoot weak staining when fixation history is uncertain?
The selected image identifies paraffin-embedded tissue but does not report its fixative, so TACR1-specific fixation sensitivity is unknown (M01006 tissue-IHC caption). Record the fixative, duration and processing history for each specimen, then compare similarly processed sections before attributing intensity differences to biology (standard IHC practice). Keep the documented EDTA retrieval at pH 8.0 and the starting antibody dilution at 1:50 constant during that comparison (M01006 tissue-IHC caption). If staining remains weak, assess section integrity and a known staining control alongside the test section; neither the tissue atlas pattern nor receptor topology establishes a fixation-specific effect (standard IHC practice; UniProt P25103 topology).
Should TACR1 staining appear at the membrane or in the cytoplasm?
TACR1 is annotated at the cell membrane and early endosomes; substance P binding can drive internalization followed by recycling (UniProt P25103 subcellular annotation). A membrane-associated pattern is therefore plausible, while intracellular signal requires attention to cell identity and morphology rather than automatic rejection (UniProt P25103 subcellular annotation; standard IHC practice). HPA reports cytoplasmic staining in squamous epithelia, with medium staining in cervix and esophagus squamous epithelial cells (HPA tissue IHC). Inspect intact cell borders and cytoplasm at the same magnification, and compare with an adjacent negative-control section before scoring diffuse chromogen deposits as receptor signal (standard IHC practice).
Can this antibody distinguish TACR1 isoforms or reveal an inaccessible epitope?
TACR1 has 2 annotated isoforms, but the supplied product caption does not identify the antibody epitope or establish isoform selectivity (UniProt P25103 isoforms; M01006 tissue-IHC caption). The receptor has 7 transmembrane segments, extracellular residues 1–31 and a cytoplasmic tail at residues 309–407 (UniProt P25103 topology). Its annotated glycosylation sites are at residues 14 and 18; these annotations alone do not show that processing masks this antibody’s unknown epitope (UniProt P25103 glycosylation; standard IHC interpretation). Seek a mapped immunogen or independent isoform-specific validation before assigning a compartmental staining difference to one isoform (standard IHC practice).
How can I check a TACR1 pattern by multiplex IF?
Use IF as a separate validation experiment and include a marker for the expected cell type, such as respiratory epithelial cells in bronchus or squamous epithelial cells in cervix (HPA tissue IHC; standard IF practice). Choose fluorophores and imaging channels after checking tissue autofluorescence with an unstained section, and acquire single-stain controls before interpreting overlap (standard IF practice). TACR1 spans the membrane 7 times; access to a cytoplasmic epitope generally requires permeabilisation, whereas an accessible extracellular epitope may be assessed without it (UniProt P25103 topology; standard IF practice). Because this antibody’s epitope is unspecified, compare permeabilised and nonpermeabilised preparations without treating either pattern as isoform proof (M01006 tissue-IHC caption; standard IF practice).
What should I change when TACR1 DAB staining is diffuse?
First inspect a no-primary control and the tissue edges to separate nonspecific deposits from cell-associated staining (standard IHC practice). The selected tissue image used 10% goat serum blocking, a 1:50 primary dilution, peroxidase-linked detection and DAB development (M01006 tissue-IHC caption). Apply an endogenous peroxidase block and keep DAB development comparable across sections; those are general chromogenic IHC steps, not evidence of TACR1-specific background (standard IHC practice). If background persists, titrate the primary around the documented starting condition while checking that expected cells retain interpretable membrane or cytoplasmic signal (M01006 tissue-IHC caption; UniProt P25103 subcellular annotation; standard IHC practice).
How should I score heterogeneous TACR1 staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, then use an H-score or percent positive cells for cell-level chromogenic staining (standard IHC practice). Record membrane-associated and cytoplasmic signal separately when both are visible, because TACR1 is annotated at the cell membrane and early endosomes (UniProt P25103 subcellular annotation; standard IHC practice). Normalize positive-cell counts to the number of evaluable cells in the same population, or report positive-cell density per mm² of viable tissue (standard IHC practice). Apply identical thresholds and exclude damaged edges and necrotic regions so processing artifacts do not drive between-section differences (standard IHC practice).
How can I distinguish true TACR1 signal from staining artefact?
Look for reproducible, cell-associated membrane or intracellular staining in morphologically intact cells, consistent with TACR1 membrane and early-endosome localisation (UniProt P25103 subcellular annotation; standard IHC practice). HPA reports medium staining in bronchus respiratory epithelial cells and several squamous epithelial populations, but its tissue-IHC assessment notes only medium agreement with RNA and awaits external verification (HPA tissue IHC). Question signal confined to section edges, necrosis or cells outside the population being scored, and compare it with a no-primary control (standard IHC practice). Peroxidase-related DAB signal and broad diffuse deposits need separate controls before they can support a TACR1-positive call (standard IHC practice).
Boster reagents
Best TACR1 / Substance-P receptor IHC Antibodies
The IHC-tested TACR1 antibody has paraffin-section images from human lung cancer and mouse and rat colon (M01006 image captions). No IF data are supplied (M01006 catalog).
Real IHC data
Anti-Neurokinin 1 Receptor Monoclonal Antibody
Cat # M01006
M01006 will render with an IHC figure from paraffin-embedded human lung cancer tissue (M01006 figure caption). Additional images show paraffin-embedded mouse and rat colon, and IHC is a listed application (M01006 image captions; M01006 catalog).
Which to pick: Choose M01006 for chromogenic IHC on paraffin sections: its figure documents EDTA retrieval at pH 8.0, a 1:50 primary dilution and peroxidase/DAB detection; the fixative is unreported (M01006 figure caption). For cross-species IHC, M01006 is a rabbit monoclonal with human, mouse and rat reactivity and corresponding paraffin-section images (M01006 catalog; M01006 image captions). There is no supported IF/ICC pick: M01006 has no listed IF application or IF image (M01006 catalog).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P25103 (NK1R_HUMAN, Substance-P receptor).
- Human Protein Atlas. TACR1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. TACR1 subcellular location (ICC-IF): Localized to the plasma membrane, centrosome and basal body..
- Human Protein Atlas. TACR1 antibody validation summary (2 antibodies).
- Post-treatment with maropitant reduces oxidative stress, endoplasmic reticulum stress and neuroinflammation on peripheral nerve injury in rats. PloS one 2024 — PMC10954158.
- Expression of Tacr1 and Gpr83 by spinal projection neurons. Molecular pain 2025 — PMC12515344.
- Long-range inhibitory neurons mediate cortical neurovascular coupling. Cell reports 2024 — PMC11168451.
- Substance P regulates Tacr1 neurons, which control nitric oxide-mediated neurovascular coupling in the mouse cortex. Science advances 2026 — PMC13330815.
- PubMed PMID:1718267 — UniProt-cited evidence.
- PubMed PMID:1659396 — UniProt-cited evidence.
- PubMed PMID:1657150 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for TACR1 (Substance-P receptor). Expected localisation Epithelial cytoplasm (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M01006). Validated IHC antibody: M01006 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Bronchus (Respiratory epithelial cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet M01006); 2. Fixation: Image fixative and duration unreported (datasheet M01006); 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 retrieval: EDTA pH 8.0 (datasheet M01006); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M01006); 8. Primary antibody: Rabbit monoclonal (clone AFBH-20) anti-TACR1, 1:50 (datasheet M01006); 9. Primary incubation: Overnight at 4 °C (datasheet M01006). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Substance P can shift receptor into early endosomes (UniProt); Isoform / epitope: 2 isoforms; map extracellular versus cytoplasmic epitopes (UniProt); Regulation: No expression regulator annotated (UniProt). Evidence: UniProt P25103, HPA tissue IHC · Enhanced, HPA ICC-IF · plasma membrane, centrosome and basal body., Datasheet M01006, PMC10954158. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/TACR1/immunohistochemistry-ihc-guide.