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CMKLR1 / Chemerin-like receptor 1 · IHC design guide
Design Immunohistochemistry for CMKLR1
Plan CMKLR1 chromogenic IHC in paraffin sections using the observed cytoplasmic tissue pattern alongside its expected membrane location (HPA tissue IHC; UniProt). This guide covers controls, fixation, detection and scoring while accounting for uncertain agreement between tissue staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CMKLR1 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 | Cell membrane expected (UniProt); cytoplasm observed (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in most tissues, including parathyroid gland (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A02960) | |
| Positive control | Kidney+2 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 conditions consistent across paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Staining has low consistency with RNA expression (HPA tissue IHC) | |
| Regulation | High in differentiating adipocytes (UniProt) | |
| Isoform / epitope | 2 isoforms; check extracellular vs cytoplasmic epitope (UniProt) |
Section 1
Recommended CMKLR1 IHC & IF Protocols
Start with the catalog antibody’s IHC-P protocol (datasheet A02960), then compare three published CMKLR1 IHC protocols (PMC10804379; PMC3670424; PMC10044805).
| Sample | Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A02960) |
| Fixation | Image fixative and duration unreported (datasheet A02960); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Tris-EDTA pH 9.0 (datasheet A02960); 20 min, 95–100 °C (standard) |
| 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-CMKLR1, 1:100 recommended; image 1:200 (datasheet A02960) |
| 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 | CMKLR1-positive staining in cells in tubules of kidney (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in most tissues, including parathyroid gland and placenta. No signal in the no-primary control. |
💡Decision noteTry heat-mediated Tris-EDTA pH 9.0 retrieval first (datasheet A02960); a published human tissue protocol also uses pH 9 (PMC10044805).
Section 2
What Is the Expected CMKLR1 Staining Pattern?
CMKLR1 is a seven-transmembrane cell-surface receptor that can internalize after chemerin stimulation (UniProt Q99788 topology and subcellular annotation). Expression is reported in monocyte-derived macrophages, immature dendritic cells and blood monocytes (UniProt Q99788 tissue specificity). HPA reports mainly cytoplasmic tissue staining, including medium staining in kidney tubules, parathyroid glandular cells and Leydig cells, but rates its tissue IHC pattern Uncertain because staining and RNA expression have low consistency (HPA tissue IHC).
| Membrane-associated staining, with some intracellular staining, in cells of an appropriate population. | This fits a cell-surface receptor that internalizes in response to RARRES2 (UniProt Q99788 subcellular annotation). HPA also describes cytoplasmic staining across most tissues (HPA tissue IHC). Judge the cell identity and distribution together; a cytoplasmic component alone cannot distinguish internalized receptor from nonspecific signal (UniProt Q99788; HPA tissue IHC). |
| Strong, isolated nuclear staining without a convincing membrane or cytoplasmic component. | A nuclear-only pattern lacks support from the annotated membrane location and HPA's cytoplasmic tissue profile (UniProt Q99788 subcellular annotation; HPA tissue IHC). Treat it as suspect and check the primary-omission control, detection reagents and morphology before assigning CMKLR1 positivity (general IHC practice). |
| Staining dominates a cell type reported as undetected, such as appendix glandular cells or bone-marrow hematopoietic cells. | HPA lists these particular cell populations as Not detected, although its overall IHC reliability is Uncertain (HPA tissue IHC). Consider cross-reactivity or endogenous detection activity; verify cell identity and compare with an omission control before interpreting the signal (general IHC practice). |
| Diffuse color covers tissue, stroma or blank areas and obscures cell boundaries. | That distribution cannot establish receptor localization or a positive cell population (general IHC practice). Background may reflect nonspecific binding or detection chemistry; inspect a primary-omission control and assess whether signal tracks tissue structures rather than individual cells (general IHC practice). |
| No staining in kidney tubule cells, parathyroid glandular cells or testicular Leydig cells. | HPA reports Medium staining in these populations, so an absent signal calls for a run check (HPA tissue IHC). Their staining is not a definitive target-positive standard because HPA rates the pattern Uncertain; review control performance and morphology before calling a sample CMKLR1-negative (HPA tissue IHC; general IHC practice). |
💡Expected CMKLR1 appearanceA plausible positive has membrane-associated staining with possible cytoplasmic signal in an appropriate cell population; HPA reports Medium staining in kidney tubule, parathyroid glandular and Leydig cells, with Uncertain reliability (UniProt Q99788 subcellular annotation; HPA tissue IHC). Diffuse background or isolated nuclear color is suspect (general IHC practice).
| Receptor location and ligand response | CMKLR1 is annotated at the cell membrane and internalizes efficiently after RARRES2 stimulation (UniProt Q99788 subcellular annotation). Thus intracellular staining can be compatible with receptor biology, but a static IHC section cannot establish whether ligand-driven internalization occurred (UniProt Q99788; general IHC practice). |
| Epitope position | The receptor has 7 transmembrane segments and extracellular and cytoplasmic regions (UniProt Q99788 topology). The supplied record does not locate the antibody epitope, so it cannot predict which region the antibody recognizes or whether retrieval changes CMKLR1 detection (UniProt Q99788 topology; supplied antibody record). |
| Tissue and cell selection | UniProt reports expression in myeloid populations and multiple organs, while HPA's scored tissue examples vary by cell type and include undetected populations (UniProt Q99788 tissue specificity; HPA tissue IHC). Record the stained cell type, not just the organ name, when comparing sections (general IHC practice). |
| Evidence strength | HPA rates tissue IHC Uncertain owing to low consistency between antibody staining and RNA data; its listed antibody HPA047865 is also IHC Uncertain (HPA tissue IHC; HPA antibodies). A visually plausible pattern therefore needs controls and cautious interpretation (general IHC practice). |
| IF/ICC Q&A: Should the tissue IHC pattern be used as an IF/ICC protocol? | No protocol inference follows from these data: HPA summarizes the ICC-IF location as membrane but supplies no main-location assignment or imaged cell lines (HPA subcellular ICC-IF). Use that location as limited context; IF/ICC assay conditions belong in the separate guide (HPA subcellular ICC-IF). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in a section chosen for expected staining. | The run may have failed, the sampled cell population may be absent, or expression may vary; HPA's medium-positive examples have Uncertain overall reliability (HPA tissue IHC; general IHC practice). | Confirm the expected cell type in the section and check a concurrently processed control. Review the validated antibody instructions and retrieval and detection steps before interpreting the sample as negative (HPA tissue IHC; general IHC practice). |
| Only nuclei appear positive. | Neither UniProt's membrane annotation nor HPA's cytoplasmic tissue profile supports a nuclear-only pattern (UniProt Q99788 subcellular annotation; HPA tissue IHC). | Compare primary-omission and stained sections, inspect precipitate or pigment, and reassess whether any cell-boundary or cytoplasmic pattern remains (general IHC practice). |
| Color persists broadly when the primary antibody is omitted. | A primary-independent signal points toward endogenous detection activity or another detection-system background source (general IHC practice). | Check the omission control beside the test section; optimize the relevant endogenous-activity block and detection reagents according to the assay chemistry (general IHC practice). |
| Color appears across many unrelated cells or extracellular areas. | Nonspecific binding or excess detection signal can obscure cell-specific staining (general IHC practice). HPA's Uncertain reliability makes appearance alone weak evidence of specificity (HPA tissue IHC). | Inspect tissue morphology and background controls, then optimize blocking, primary concentration and detection development within the validated IHC workflow (general IHC practice). |
| A reportedly undetected HPA cell population stains strongly. | HPA reports several cell-specific negative findings, but its tissue IHC pattern is Uncertain; cross-reactivity, endogenous activity or biological variation remain possible (HPA tissue IHC; general IHC practice). | Verify the exact cell population and compare matched controls. Describe the observation without converting an HPA negative listing into a definitive exclusion rule (HPA tissue IHC; general IHC practice). |
| Cytoplasmic staining is present with little visible membrane outline. | HPA reports cytoplasmic tissue staining, and UniProt notes receptor internalization after RARRES2 stimulation; neither establishes the mechanism in this section (HPA tissue IHC; UniProt Q99788 subcellular annotation). | Score the cell type and intracellular distribution, check background controls, and report the pattern as observed without assigning ligand exposure or internalization from IHC alone (general IHC practice). |
Experiment evidence
IHC & IF images showing CMKLR1 staining
A02960 · IHCImmunohistochemical analysis of paraffin-embedded human tonsil. 1, Antibody was diluted at 1:200 (4° overnight). 2, Tris-EDTA,pH9.0 was used
A02960 · IFImmunofluorescence analysis of A549. 1,primary Antibody (red) was diluted at 1:200 (4°C overnight). 2, Goat Anti Rabbit IgG (H&L) - Alexa Fl
A02960-1 · IHCImmunohistochemistry (IHC) analyzes of ChemR23 (R249) pAb in paraffin-embedded human kidney carcinoma tissue at 1:50.showing cytoplasmic and
A02960-1 · IHCImmunohistochemistry (IHC) analyzes of ChemR23 (R249) pAb in paraffin-embedded human stomach carcinoma tissue at 1:50.showing cytoplasmic an
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000174600-CMKLR1/tissue/cerebral+cortex#imid_13446532
HPA · Parathyroid glandHuman Protein Atlas IHC, Parathyroid gland. Source: https://www.proteinatlas.org/ENSG00000174600-CMKLR1/tissue/parathyroid+gland#imid_13415954
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000174600-CMKLR1/tissue/colon#imid_13415997
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000174600-CMKLR1/tissue/liver#imid_13415990
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CMKLR1 IHC & IF
🧪Run kidney first: tubular cells should stain at the HPA Medium level (HPA: kidney, cells in tubules, Medium). Use bronchus respiratory epithelial cells as the negative tissue (HPA: bronchus, respiratory epithelial cells, Not detected); on the kidney slide, cells used as internal negative comparators should show counterstain and background only, without specific chromogen deposition (standard IHC practice).
Positive control tissue: Kidney (Cells in tubules, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for CMKLR1; derive a cell-line control from the positive tissue's cell type (Cells in tubules) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and an irrelevant isotype control matched to the primary antibody’s host species and immunoglobulin class (standard IHC practice). Add a CMKLR1 knockout sample or a peptide-block control where a suitable immunizing peptide is available, and quench endogenous peroxidase in kidney sections; block endogenous biotin if using avidin–biotin detection (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and fixation effect are unreported, and the selected A02960 paraffin-section caption does not state a fixative (A02960 tissue-IHC caption). The caption uses Tris-EDTA at pH 9.0 for antigen retrieval, but does not establish whether retrieval is required under other conditions (A02960 tissue-IHC caption). Whether frozen sections or IF are easier is unestablished; no HPA ICC-IF cell-line images are supplied (HPA: subcellular record), and kidney sections may have endogenous peroxidase or biotin background (standard IHC practice).
HPA tissue IHC evidence for CMKLR1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — 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 |
|---|---|---|---|---|
| Kidney | Cells in tubules | Medium | Protein (IHC) | HPA → |
| Parathyroid gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Testis | Leydig cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | 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 → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CMKLR1 IHC Tips
These questions address paraffin-section chromogenic IHC for CMKLR1, with one entry on adapting the analysis to IF.
Which retrieval conditions should I start with for CMKLR1 in paraffin sections?
Start with heat-mediated retrieval in Tris-EDTA at pH 9.0 for the catalog antibody (datasheet A02960). The selected paraffin-embedded human tonsil image used that buffer, a 1:200 primary dilution overnight at 4°C, and a 1:200 secondary for 45 minutes at room temperature (caption A02960). If staining is weak, compare a gentler retrieval condition on adjacent sections while holding antibody concentration and detection constant; record any change in tissue morphology. Assess cellular pattern as well as intensity, because CMKLR1 is a membrane receptor that can internalize after RARRES2 stimulation (UniProt Q99788 localisation).
How should I troubleshoot weak staining when the specimen fixative is uncertain?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative (caption A02960). Record the specimen’s actual fixative and processing history before comparing slides, then stain adjacent sections with identical retrieval, antibody incubation, and detection settings. If signal differs across preparations, compare matched tissue processed under documented conditions and inspect morphology; that comparison can identify a processing-associated difference without assigning a CMKLR1-specific mechanism. Use the catalog image’s pH 9.0 Tris-EDTA retrieval and 1:200 primary dilution as documented starting conditions (caption A02960), while treating any fixation adjustment as an experiment requiring its own controls.
Should CMKLR1 staining be membranous or cytoplasmic in chromogenic IHC?
CMKLR1 is annotated at the cell membrane and can internalize efficiently in response to RARRES2 (UniProt Q99788 localisation). Its 7 transmembrane segments support careful assessment of membrane-associated staining, but a cytoplasmic signal alone cannot establish receptor identity (UniProt Q99788 topology). The tissue atlas reports broadly cytoplasmic staining while rating its tissue IHC reliability uncertain because staining and RNA expression have low consistency (HPA tissue IHC). Score membrane and cytoplasmic compartments separately in intact cells, compare adjacent sections and appropriate controls, and avoid interpreting diffuse chromogen deposits or staining outside cell boundaries as CMKLR1.
Could isoforms or epitope position explain different CMKLR1 staining patterns?
CMKLR1 has 2 annotated isoforms, A and B, but the supplied product caption does not identify the antibody epitope or establish isoform recognition (UniProt Q99788 isoforms; caption A02960). The receptor has extracellular residues 1–41 and a cytoplasmic tail at 321–373, so epitope location would affect how staining responds to processing and antibody access (UniProt Q99788 topology). Glycosylation sites at residues 9 and 192 and several tail phosphorylation sites are annotated; their effect on this antibody’s staining is untested here (UniProt Q99788 modifications). Check the antibody’s epitope documentation before making isoform-specific or modification-specific claims, and report the observed compartment without assigning an unsupported molecular cause.
How can I adapt CMKLR1 localisation analysis to multiplex IF?
For a separate IF assay, pair CMKLR1 with a macrophage marker such as CD68, since monocyte-derived macrophages are an abundant CMKLR1-expressing leukocyte population (UniProt Q99788 tissue specificity). Choose spectrally separated fluorophores and consider a red or far-red CMKLR1 channel if the specimen has strong short-wavelength autofluorescence; inspect unstained tissue in each channel first (standard IF practice). CMKLR1 has extracellular loops and a cytoplasmic tail, but the antibody’s epitope side is unspecified, so establish it before choosing whether permeabilisation is needed (UniProt Q99788 topology; caption A02960). Compare conditions with and without mild permeabilisation, retain single-stain controls, and evaluate membrane-associated and intracellular signals separately (standard IF practice).
What should I check when CMKLR1 chromogenic staining looks diffuse or widespread?
First inspect a no-primary control for secondary-reagent signal, endogenous peroxidase activity, and chromogen deposits, using the same detection and counterstain sequence (standard IHC practice). Check whether tissue edges, folds, damaged areas, or necrotic regions carry stronger signal than well-preserved cells, and exclude those areas from scoring. The catalog image used a 1:200 primary dilution overnight at 4°C; titrate around that documented condition if intact-cell staining is obscured (caption A02960). Widespread cytoplasmic staining deserves particular caution because the tissue atlas reports that pattern with uncertain IHC reliability and low staining–RNA consistency (HPA tissue IHC).
How should I quantify CMKLR1 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define cell populations and regions before scoring, then record the percentage of positive intact cells and staining intensity to calculate an H-score on a 0–300 scale (standard IHC practice). Report membrane-associated and cytoplasmic scores separately, since CMKLR1 is membrane-localized and can internalize after RARRES2 stimulation (UniProt Q99788 localisation). For sparse immune cells, count positive cells per mm² of evaluable tissue and normalize to the density of the relevant cell population when available (standard IHC practice). Apply identical thresholds, section inclusion rules, retrieval, and detection settings across groups, and disclose that tissue atlas IHC reliability is uncertain (HPA tissue IHC).
What evidence distinguishes genuine CMKLR1 staining from a tissue artefact?
Look for reproducible staining in intact cells with a plausible membrane-associated pattern, allowing for intracellular signal because CMKLR1 can internalize after RARRES2 stimulation (UniProt Q99788 localisation). Monocyte-derived macrophages and immature dendritic cells are plausible positive populations, but cell identity must be established by morphology or an independent marker (UniProt Q99788 tissue specificity). Discount isolated edge staining, necrotic deposits, and signal reproduced in a no-primary control; endogenous peroxidase can create false chromogenic signal without adequate blocking (standard IHC practice). Interpret negatives cautiously: the tissue atlas rates CMKLR1 IHC uncertain despite reporting medium staining in kidney tubules and parathyroid glandular cells (HPA tissue IHC).
Boster reagents
Best CMKLR1 / Chemerin-like receptor 1 IHC Antibodies
Two anti-CMKLR1 antibodies have IHC images from paraffin-embedded human tissue; one also has an IF image from A549 cells (catalog image captions). Both list human, mouse and rat reactivity (catalog).
Real IHC data
Anti-ChemR23 CMKLR1 Antibody
Cat # A02960
Real IHC data
Anti-ChemR23 (R249) CMKLR1 Antibody
Cat # A02960-1
A02960 will render with human tonsil IHC; its catalog also shows A549 IF (A02960 image captions). A02960-1 will render with human kidney carcinoma IHC; its catalog also shows human stomach carcinoma IHC (A02960-1 image captions).
Which to pick: For paraffin-section IHC, choose A02960 for the tonsil example or A02960-1 for the kidney carcinoma example; both captions report paraffin embedding, but neither reports the fixative (IHC image captions). For IF/ICC, start with A02960 because it has an A549 IF image; A02960-1 lists IF as an application but has no IF image in the payload (catalog). For mouse or rat samples, either SKU lists reactivity, though the supplied IHC images show human tissue only (catalog reactivity; IHC image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q99788 (CML1_HUMAN, Chemerin-like receptor 1).
- Human Protein Atlas. CMKLR1 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. CMKLR1 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. CMKLR1 antibody validation summary (1 antibodies).
- Chemokine‑like receptor 1‑positive cells are present in the odontoblast layer in tooth tissue in rats and humans. Experimental and therapeutic medicine 2024 — PMC10804379.
- The Regulatory Roles of Chemerin-Chemokine-Like Receptor 1 Axis in Placental Development and Vascular Remodeling During Early Pregnancy. Frontiers in cell and developmental biology 2022 — PMC9152263.
- Adiponectin upregulates hepatocyte CMKLR1 which is reduced in human fatty liver. Molecular and cellular endocrinology 2012 — PMC3670424.
- Chemerin and Chemokine-like Receptor 1 Expression Are Associated with Hepatocellular Carcinoma Progression in European Patients. Biomedicines 2023 — PMC10044805.
- PubMed PMID:9144535 — UniProt-cited evidence.
- PubMed PMID:9603476 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CMKLR1 (Chemerin-like receptor 1). Expected localisation Cell membrane expected (UniProt); cytoplasm observed (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A02960). Validated IHC antibody: A02960 at 1:100 recommended; image 1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Kidney (Cells in tubules); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A02960); 2. Fixation: Image fixative and duration unreported (datasheet A02960); 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: Tris-EDTA pH 9.0 (datasheet A02960); 20 min, 95–100 °C (standard); 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-CMKLR1, 1:100 recommended; image 1:200 (datasheet A02960); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation conditions consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Staining has low consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 2 isoforms; check extracellular vs cytoplasmic epitope (UniProt); Regulation: High in differentiating adipocytes (UniProt). Evidence: UniProt Q99788, HPA tissue IHC · Uncertain, HPA ICC-IF · Membrane, Datasheet A02960, PMC10804379, PMC3670424. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CMKLR1/immunohistochemistry-ihc-guide.