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SCARB1 / Scavenger receptor class B member 1 · IHC design guide
Design Immunohistochemistry for SCARB1
Plan chromogenic SCARB1 IHC in paraffin sections with fixation, retrieval, and staining controls. Compare the expected membranous pattern with staining in adrenal zona fasciculata and testis Leydig cells (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SCARB1 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 in a subset of tissues (HPA tissue IHC) | |
| Staining pattern | Membranous in adrenal zona fasciculata and testis Leydig cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific) | |
| Caveat | Presumed off-target GI staining can mislead (HPA tissue IHC) | |
| Regulation | No specific expression regulator given (UniProt) | |
| Isoform / epitope | 5 isoforms; verify extracellular vs cytoplasmic epitope (UniProt) |
Section 1
Recommended SCARB1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is followed by three published SCARB1 chromogenic IHC protocols (PMC8741905; PMC12010815; PMC9907373).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A01093); 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-SCARB1, 2.5 μg/mL (datasheet A01093) |
| 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 | SCARB1-positive staining in cells in zona fasciculata of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Membranous expression in a subset of tissues, including adrenal gland, Leydig cells, sinusoids in liver, vessels in placenta and salivary ducts. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page retrieval guidance); adjust for the antibody and detection system used.
Section 2
What Is the Expected SCARB1 Staining Pattern?
SCARB1 is a membrane receptor with two transmembrane segments and a large extracellular region (UniProt Q8WTV0 topology). Expect chiefly membranous staining in selected tissues, especially adrenal zona fasciculata cells and testicular Leydig cells (HPA: High in both). HPA rates tissue IHC reliability Enhanced, while noting medium consistency with RNA expression and presumed off-target binding in the GI tract (HPA tissue IHC).
| Distinct membranous staining in adrenal zona fasciculata cells or Leydig cells. | This matches two HPA High cell populations and the reported membranous tissue pattern (HPA tissue IHC). Compare the stained cells with tissue morphology when scoring (general IHC practice). |
| Strong staining confined to nuclei, with no corresponding membranous pattern. | An exclusively nuclear result does not match SCARB1's reported cell-membrane location (UniProt Q8WTV0) or HPA tissue IHC. Review the negative control and antibody specificity (general IHC practice). |
| Strong staining in duodenal glandular cells or colonic endothelial cells. | HPA reports these cells as Not detected and flags presumed off-target GI binding (HPA tissue IHC). Treat this pattern cautiously; compare it with an HPA High cell population and appropriate controls. |
| Diffuse chromogen across cells and surrounding tissue, obscuring cell borders. | This is difficult to score as the reported membranous pattern (HPA tissue IHC). Background can arise from nonspecific antibody binding or detection activity; inspect a negative control (general IHC practice). |
| No staining in adrenal zona fasciculata cells or Leydig cells. | These are HPA High populations, so a blank result needs a technical check (HPA tissue IHC). Verify tissue identity, controls, retrieval, primary-antibody incubation and detection (general IHC practice). |
💡Expected SCARB1 appearanceCall positive when membranous signal is clear in HPA High adrenal zona fasciculata cells or Leydig cells; diffuse tissue-wide or exclusively nuclear staining does not match that pattern (HPA tissue IHC; UniProt Q8WTV0).
| Membrane topology and epitope location (UniProt Q8WTV0 topology). | SCARB1 has extracellular residues 33–443 and cytoplasmic ends (UniProt Q8WTV0 topology). Interpret staining against the antibody's stated epitope, if available; this record does not locate that epitope. |
| Uneven expression across tissues (HPA tissue IHC). | HPA reports High staining in adrenal zona fasciculata cells and Leydig cells, Medium in kidney proximal-tubule cell bodies and placental trophoblasts, and Not detected in several listed populations (HPA tissue IHC). |
| Antibody validation and GI caveat (HPA antibodies; HPA tissue IHC). | Two listed antibodies have Enhanced IHC validation, yet HPA notes medium consistency with RNA expression and disregarded presumed off-target GI staining (HPA tissue IHC). Assess unexpected GI signal against this caveat. |
| IF/ICC Q: Should an IF vesicle signal be scored as the expected IHC pattern? | A: HPA reports vesicles as the main approved ICC-IF location, with additional lysosome and rods-and-rings locations; tissue IHC is described as membranous (HPA subcellular; HPA tissue IHC). Interpret each application in its own context. |
| Target-specific fixation sensitivity. | The supplied UniProt and HPA records do not report a SCARB1-specific fixation effect. Evaluate retrieval and processing with routine IHC controls without assigning a SCARB1-specific cause (general IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected-positive adrenal or testis section is blank (HPA: High). | The result conflicts with HPA High staining; the cause is unresolved by these records (HPA tissue IHC). | Confirm the expected cell population, then check section quality, retrieval, primary-antibody step and detection controls (general IHC practice). |
| Membrane staining is weak in an HPA High population. | A weak result differs from HPA's High category, but HPA does not identify the cause in this specimen (HPA tissue IHC). | Compare a matched positive control and review retrieval, antibody incubation and detection settings (general IHC practice). |
| Only nuclear staining appears. | This conflicts with the reported membrane location (UniProt Q8WTV0; HPA tissue IHC). | Check the negative control, examine the correct cell population and reassess antibody specificity before scoring positive (general IHC practice). |
| Strong GI staining appears in cells listed as Not detected. | HPA notes presumed off-target GI binding and lists duodenal glandular cells as Not detected (HPA tissue IHC). | Record the cell type and compare negative controls and an HPA High tissue; do not assign that GI signal to SCARB1 without corroboration. |
| Chromogen covers the section diffusely. | Diffuse background obscures the cell-specific, membranous pattern reported by HPA (HPA tissue IHC). | Inspect a no-primary control and review blocking, washes, antibody concentration and chromogen development (general IHC practice). |
| Placental or kidney staining seems weaker than adrenal staining. | HPA rates placental trophoblasts and kidney proximal-tubule cell bodies Medium, versus High in adrenal zona fasciculata cells (HPA tissue IHC). | Identify the scored cell population first; compare like tissues and controls before treating the intensity difference as a failed run (general IHC practice). |
Experiment evidence
IHC & IF images showing SCARB1 staining
A01093 · IHCImmunohistochemistry of SCARB1 in human spleen tissue with SCARB1 antibody at 2.5 μg/mL.
A01093 · IFImmunofluorescence of SCARB1 in Human Spleen tissue with SCARB1 antibody at 20 μg/mL.
M01093 · IHCImmunohistochemical analysis of paraffin-embedded human liver, using SCARB1 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000073060-SCARB1/tissue/cerebral+cortex#imid_20517923
HPA · Adrenal glandHuman Protein Atlas IHC, Adrenal gland. Source: https://www.proteinatlas.org/ENSG00000073060-SCARB1/tissue/adrenal+gland#imid_1127
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000073060-SCARB1/tissue/colon#imid_20517841
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000073060-SCARB1/tissue/liver#imid_20517834
HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA066285; green = SCARB1, blue = nucleus, red = microtubules.
HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA066285; green = SCARB1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SCARB1 IHC & IF
🧪Run adrenal gland first: cells in the zona fasciculata should stain (HPA: High in cells in zona fasciculata). Use adipose tissue adipocytes as the negative comparison (HPA: Not detected in adipocytes); on the adrenal slide, cells lacking specific signal should show counterstain without distinct chromogenic staining (standard IHC practice), but no other adrenal cell type is established as SCARB1-negative by the supplied HPA rows.
Positive control tissue: Adrenal gland (Cells in zona fasciculata, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SCARB1 in CACO-2, SK-MEL-30, U2OS, with annotated localisation: Vesicles (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species and clonality (standard IHC practice); use SCARB1 knockout tissue or a validated immunizing-peptide block as a biological specificity control if available (standard IHC practice). Check the adrenal section for endogenous peroxidase signal in the no-primary control (standard chromogenic IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the A01093 spleen IHC caption does not state a fixative (selected-SKU caption: fixative not stated). Antigen-retrieval dependence is unreported in the supplied evidence (supplied target/application evidence: no retrieval condition). The supplied evidence does not establish whether frozen sections or IF are easier than paraffin IHC; HPA shows ICC-IF images in CACO-2, SK-MEL-30 and U2OS (HPA subcellular), while endogenous peroxidase is a potential chromogenic background source to check on the adrenal control (standard IHC practice).
HPA tissue IHC evidence for SCARB1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Presumed off target binding in GI tract observed and disregarded.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adrenal gland | Cells in zona fasciculata | High | Protein (IHC) | HPA → |
| Bronchus | Ciliated cells (cilia axoneme) | High | Protein (IHC) | HPA → |
| Fallopian tube | Ciliated cells (cilia axoneme) | High | Protein (IHC) | HPA → |
| Testis | Leydig cells | High | Protein (IHC) | HPA → |
| Kidney | Proximal tubules (cell body) | 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 → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SCARB1 IHC Tips
Troubleshoot SCARB1 chromogenic IHC in paraffin sections using matched controls, expected cell types and compartment patterns; IF considerations appear in one separate entry.
How should I optimise retrieval when SCARB1 staining is weak?
Start with citrate pH 6.0 heat induced retrieval at 95–98 °C for 20 min (page retrieval rule: membrane antigen). Keep section thickness, cooling and detection conditions matched while comparing retrieval runs, so changes in staining can be attributed to retrieval (standard IHC practice). Assess the membrane pattern in adrenal zona fasciculata cells or testicular Leydig cells alongside a negative control section (HPA: high staining in both cell types; standard IHC practice). If staining remains weak, test a longer citrate retrieval run on adjacent sections and reject conditions that increase diffuse background or damage tissue morphology (standard IHC practice).
Could fixation explain weak or patchy SCARB1 staining?
Target specific fixation sensitivity is unknown because the supplied tissue image caption does not state its fixative (A01093 tissue IHC caption). Record the fixative, fixation interval and processing history for each paraffin block before attributing uneven staining to antigen loss (standard IHC practice). Compare adjacent sections from blocks with known, similar processing using the same citrate pH 6.0 retrieval and detection run (page retrieval rule; standard IHC practice). Include a positive control with the expected cellular pattern, and interpret any improvement alongside tissue preservation and background staining (HPA: high in adrenal zona fasciculata cells and Leydig cells; standard IHC practice).
Should SCARB1 appear at the membrane or inside cells?
Expect a membrane associated pattern in chromogenic tissue IHC, especially in the cell types reported by the tissue atlas (HPA: membranous expression in a subset of tissues). SCARB1 has 2 transmembrane segments and a large extracellular region spanning residues 33–443 (UniProt Q8WTV0 topology). Its reported enrichment in caveolae can make membrane staining appear uneven rather than forming a continuous outline (UniProt Q8WTV0 subcellular location). Vesicular staining can also be biologically plausible, but that observation comes from cell based IF; assess it against membrane staining, morphology and controls before assigning it in paraffin sections (HPA subcellular: vesicles; standard IHC practice).
How do isoforms and epitope position affect SCARB1 IHC?
SCARB1 has 5 annotated isoforms, so confirm which sequences the antibody immunogen covers before comparing tissue staining across experiments (UniProt Q8WTV0 isoforms; standard IHC practice). The main extracellular region spans residues 33–443, whereas residues 465–552 are cytoplasmic (UniProt Q8WTV0 topology). Nine annotated glycosylation sites fall within the extracellular region, which makes epitope mapping relevant when interpreting antibody accessibility (UniProt Q8WTV0 glycosylation and topology). The supplied evidence does not map this antibody’s epitope or establish isoform selectivity; use the antibody’s documented immunogen and appropriate tissue controls when investigating discrepant IHC patterns (supplied product evidence; standard IHC practice).
How can I check SCARB1 localisation by multiplex IF?
Use IF on a separate, validated preparation to examine whether SCARB1 signal overlaps a marker identifying an expected positive cell type, such as Leydig cells (HPA: high in Leydig cells; standard IF practice). Choose spectrally separated fluorophores, favouring a far red SCARB1 channel if the specimen has strong shorter wavelength autofluorescence (standard IF practice). Check the antibody’s epitope location before permeabilising: access to a cytoplasmic epitope requires permeabilisation, whereas an extracellular epitope may be assessed without it (UniProt Q8WTV0 topology; standard IF practice). Compare single stain, secondary only and autofluorescence controls, and treat vesicular IF patterns as supporting evidence rather than a direct substitute for paraffin IHC localisation (HPA subcellular: vesicles; standard IF practice).
What causes diffuse or misleading SCARB1 chromogenic staining?
First compare the suspect section with a no primary control and a known positive tissue processed in the same run (standard IHC practice). Block endogenous peroxidase before enzyme based chromogenic detection, and inspect whether pigment or precipitated chromogen is being mistaken for cellular signal (standard IHC practice). Titrate antibody concentration and detection time while retaining visible staining in the expected cells; the supplied human spleen image used 2.5 µg/mL, without reporting its fixative (A01093 tissue IHC caption). Treat gastrointestinal staining cautiously because the tissue atlas reports presumed off target binding there, and confirm any unexpected pattern with independent evidence (HPA tissue reliability description; standard IHC practice).
How should SCARB1 staining be scored across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and anatomical region before scoring, because reported SCARB1 staining varies by tissue and cell type (HPA tissue IHC profile; standard IHC practice). For chromogenic IHC, record the percentage of positive viable target cells and intensity grades, then calculate an H score from 0–300 when intensity scoring is reproducible (standard IHC practice). For spatially restricted staining, report positive cells per mm² of viable tissue and normalise to the assessed tissue area or relevant cell count (standard IHC practice). Keep retrieval, illumination, threshold and observer rules consistent, and report membrane and cytoplasmic staining separately when both occur (standard IHC practice; UniProt Q8WTV0 subcellular location).
When is an unexpected SCARB1 positive result credible?
Start with the expected membrane associated pattern and the specific cells present in the section: adrenal zona fasciculata cells and Leydig cells show high reported staining (HPA tissue IHC profile). A strong signal in a cell population reported as undetected, such as adipocytes in adipose tissue, needs confirmation before it is called SCARB1 positive (HPA: adipocytes not detected; standard IHC practice). Review edge accentuation, necrotic areas, pigment and endogenous enzyme activity against the no primary control (standard IHC practice). Vesicular signal alone needs careful interpretation because vesicles are reported from cell based IF, while presumed off target gastrointestinal staining limits confidence in that tissue (HPA subcellular; HPA tissue reliability description).
Boster reagents
Best SCARB1 / Scavenger receptor class B member 1 IHC Antibodies
Two anti-SCARB1 antibodies have human tissue IHC images; one also has a human spleen IF image (catalog image captions). Both list Human, Mouse and Rat reactivity (catalog applications/reactivity).
Real IHC data
Anti-SCARB1 Antibody
Cat # A01093
Real IHC data
Anti-SCARB1/Sr Bi Rabbit Monoclonal Antibody
Cat # M01093
A01093 has IHC and IF images from human spleen tissue (A01093 image captions). M01093 has an IHC image from paraffin-embedded human liver and lists ICC/IF among its applications (M01093 image caption; catalog applications).
Which to pick: For tissue IHC, choose A01093 for the demonstrated human spleen sample at 2.5 μg/mL (A01093 IHC image caption), or M01093 for the demonstrated paraffin-embedded human liver sample at 1:50–1:200; the latter caption does not report the fixative (M01093 IHC image caption; catalog dilution). For IF, A01093 has a human spleen image at 20 μg/mL; for ICC/IF, M01093 lists both applications and a 1:50–1:200 dilution, but has no IF image in the payload (A01093 IF image caption; M01093 catalog applications/dilution/image captions). Both list Human, Mouse and Rat reactivity; M01093 is monoclonal, while A01093 has no clone listed, and the supplied tissue images show only human samples (catalog reactivity/clone; image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q8WTV0 (SCRB1_HUMAN, Scavenger receptor class B member 1).
- Human Protein Atlas. SCARB1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SCARB1 subcellular location (ICC-IF): Mainly localized to vesicles. In addition localized to the lysosomes and rods & rings..
- Human Protein Atlas. SCARB1 antibody validation summary (3 antibodies).
- Cholesterol Auxotrophy as a Targetable Vulnerability in Clear Cell Renal Cell Carcinoma. Cancer discovery 2021 — PMC8741905.
- Scavenger receptor class B member 1 promotes lung cancer growth and metastasis through enhanced twist family BHLH transcription factor 1 signaling in vitro and in vivo: Exploration of RPPNs as a therapeutic Strategy. CytoJournal 2025 — PMC12010815.
- Integrated Whole-Exome and Transcriptome Sequencing Indicated Dysregulation of Cholesterol Metabolism in Eyelid Sebaceous Gland Carcinoma. Translational vision science & technology 2023 — PMC9907373.
- Prolactin receptor in primary hyperparathyroidism--expression, functionality and clinical correlations. PloS one 2012 — PMC3350524.
- PubMed PMID:7689561 — UniProt-cited evidence.
- PubMed PMID:16541075 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SCARB1 (Scavenger receptor class B member 1). Expected localisation Membranous in a subset of tissues (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A01093 at 2.5 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Cells in zona fasciculata); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet A01093); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat-induced epitope retrieval in citrate buffer, pH 6.0 , 20 min at 95–98 °C…; 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-SCARB1, 2.5 μg/mL (datasheet A01093); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Presumed off-target GI staining can mislead (HPA tissue IHC); Isoform / epitope: 5 isoforms; verify extracellular vs cytoplasmic epitope (UniProt); Regulation: No specific expression regulator given (UniProt). Evidence: UniProt Q8WTV0, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to vesicles. In addition localized to the lysosomes…, Datasheet A01093, PMC8741905, PMC12010815. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SCARB1/immunohistochemistry-ihc-guide.