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FADS1 / Acyl-CoA (8-3)-desaturase · IHC design guide
Design Immunohistochemistry for FADS1
Plan paraffin-section FADS1 IHC using a 1:50 starting dilution for M02535 (datasheet). Score cytoplasmic staining in adipocytes and glandular cells (HPA tissue IHC), while accounting for low agreement between antibody staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
FADS1 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); ER and mitochondrion (UniProt) | |
| Staining pattern | Cytoplasmic staining in adipocytes and glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M02535) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Soft tissue |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Antibody staining has low agreement with RNA expression (HPA tissue IHC) | |
| Regulation | Expression regulation not specified (UniProt) | |
| Isoform / epitope | Two isoforms; epitope coverage is unspecified (UniProt) |
Section 1
Recommended FADS1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by three published FADS1 staining protocols for mouse eye sections and tumor specimens (datasheet M02535; PMC12136103; PMC4934030; PMC12905685).
| Sample | Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet M02535) |
| Fixation | Image fixative and duration unreported (datasheet M02535); 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 M02535); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M02535) |
| Primary antibody | Rabbit monoclonal (clone 26F55) anti-FADS1, 1:50 (datasheet M02535) |
| Primary incubation | Overnight at 4 °C (datasheet M02535) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet M02535) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | FADS1-positive staining in adipocytes of adipose tissue (HPA tissue IHC: Medium). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet M02535); citric acid microwave retrieval for 15 minutes is a published alternative (PMC4934030 IHC methods).
Section 2
What Is the Expected FADS1 Staining Pattern?
FADS1 is an endoplasmic reticulum membrane protein also annotated in mitochondria, with four transmembrane segments (UniProt O60427). In paraffin sections, expect predominantly cytoplasmic staining in relevant cells: HPA reports general cytoplasmic expression and medium staining in adipocytes, adrenal glandular cells, respiratory epithelial cells and cortical glia (HPA tissue IHC). Its tissue IHC status is Approved, with low consistency between antibody staining and RNA expression (HPA tissue IHC).
| Cytoplasmic signal in adipocytes or adrenal glandular cells, with nuclei largely clear. | This fits the reported general cytoplasmic pattern and medium staining in those cells (HPA tissue IHC). Assess the specific cells stained and their intensity, rather than calling an entire section uniformly positive. |
| Signal is confined to nuclei, with little or no cytoplasmic staining. | A nuclear-only pattern conflicts with the reported cytoplasmic IHC profile (HPA tissue IHC) and membrane-associated locations (UniProt O60427). Review staining specificity and section quality before interpreting it as FADS1. |
| Strong staining appears in a cell population where the reference reports no detection. | Peripheral nerve in soft tissue is reported as not detected (HPA tissue IHC). Unexpected staining there warrants checks for cross-reactivity or endogenous detection activity; that reference does not make all soft tissue a negative control. |
| Chromogen spreads across stroma, empty spaces or many cell types without clear cell boundaries. | Diffuse, poorly localised colour is less consistent with the general cytoplasmic profile (HPA tissue IHC). Consider nonspecific antibody binding, inadequate washing or detection background (general IHC practice). |
| No signal appears in adipocytes and adrenal glandular cells in an otherwise interpretable run. | Both are reported at medium intensity (HPA tissue IHC), so an absent result prompts a technical check. Because antibody staining and RNA data have low consistency, do not infer biological absence from one failed section (HPA tissue IHC). |
💡Expected FADS1 appearanceCall a result positive when identifiable cells show predominantly cytoplasmic, membrane-associated staining, around medium intensity in HPA-listed adipocytes or adrenal glandular cells (HPA tissue IHC; UniProt O60427); nuclear-only colour or diffuse cell-free deposit is suspect (general IHC interpretation).
| Compartment and epitope location | Four membrane-spanning segments and cytoplasmic and lumenal regions are annotated (UniProt O60427 topology). The supplied record gives no antibody epitope, so topology cannot predict whether a particular retrieval condition exposes it. |
| Choice of reference cells | Medium staining is reported in several cell types, including adipocytes, adrenal glandular cells and cortical glia (HPA tissue IHC). Peripheral nerve in soft tissue is reported as not detected (HPA tissue IHC); compare the named cells, not whole tissues. |
| Strength of tissue-pattern evidence | The tissue IHC profile is Approved but has low consistency with RNA expression (HPA tissue IHC). HPA042705 is listed as IHC Approved, without an Enhanced designation in the supplied antibody record (HPA antibodies). Treat unexpected cell patterns cautiously. |
| Isoforms and processing | Two isoforms are listed, with no signal peptide, propeptide or cleaved chain annotated (UniProt O60427). The supplied evidence does not locate the antibody epitope or establish isoform-specific staining; avoid assigning a colour pattern to one isoform. |
| IF/ICC: should its pattern match IHC? | HPA summarises the subcellular result as membrane, but provides no main location or cell-line ICC-IF images (HPA subcellular). The supplied antibody record lists IHC Approved and no ICC status (HPA antibodies), so this IHC pattern is not an IF/ICC validation. |
| Retrieval and fixation evidence | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. |
| Situation | Likely cause | Next action |
|---|---|---|
| A known-positive cell population is unstained. | The assay may have failed, or the tested section may differ from the HPA example; medium staining is reported in adipocytes and adrenal glandular cells (HPA tissue IHC). | Run a listed positive tissue alongside the test section; check antibody application, detection reagents and counterstain, then compare retrieval conditions with matched controls (general IHC practice). |
| Colour appears mainly in nuclei. | This disagrees with HPA's general cytoplasmic profile (HPA tissue IHC) and UniProt's membrane-associated locations (UniProt O60427). Nonspecific staining or misidentified pigment is possible (general IHC interpretation). | Inspect a counterstained section and a no-primary control; interpret FADS1 only where cell boundaries and cytoplasmic signal are convincing (general IHC practice). |
| Peripheral nerve shows conspicuous signal. | Peripheral nerve in soft tissue is reported as not detected (HPA tissue IHC). Cross-reactivity or endogenous detection activity is possible, but a single discordant section cannot identify the cause. | Compare a matched no-primary control and another HPA-listed cell population; if the signal persists only with primary antibody, assess antibody specificity (general IHC practice). |
| Diffuse chromogen obscures cell-level scoring. | Background may arise from nonspecific binding, insufficient washing or endogenous detection activity (general IHC practice); it does not match the reported general cytoplasmic profile (HPA tissue IHC). | Use a no-primary control to localise background, then review blocking, washes and chromogen development before rescoring identifiable cells (general IHC practice). |
| A tissue looks weaker than expected from UniProt's expression summary. | UniProt reports highest expression in liver, brain, adrenal gland and heart (UniProt O60427), while HPA's IHC antibody staining has low consistency with RNA data (HPA tissue IHC). | Score the observed cell type against HPA's tissue IHC examples and record intensity separately; do not convert a tissue-level expression statement into a required chromogenic score. |
| A retested section changes after antigen retrieval is adjusted. | Retrieval can alter a general IHC assay's staining, but the supplied sources report no FADS1-specific fixation or retrieval effect (general IHC practice; UniProt O60427; HPA tissue IHC). | Compare conditions on matched sections with positive and no-primary controls; choose a condition that preserves interpretable cellular staining (general IHC practice). |
Experiment evidence
IHC & IF images showing FADS1 staining
M02535 · IHCIHC analysis of FADS1 using anti-FADS1 antibody (M02535). FADS1 was detected in a paraffin-embedded section of human liver cancer tissue. He
M02535 · IHCIHC analysis of FADS1 using anti-FADS1 antibody (M02535). FADS1 was detected in a paraffin-embedded section of human liver tissue. Heat medi
A02535-1 · IHCIHC analysis of FADS1 using anti-FADS1 antibody (A02535-1). FADS1 was detected in a paraffin-embedded section of human liver cancer tissue.
A02535-1 · IHCIHC analysis of FADS1 using anti-FADS1 antibody (A02535-1). FADS1 was detected in a paraffin-embedded section of human lung cancer tissue. H
A02535-1 · IFIF analysis of FADS1 using anti-FADS1 antibody (A02535-1). FADS1 was detected in a paraffin-embedded section of human ovarian cancer tissue.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000149485-FADS1/tissue/cerebral+cortex#imid_11195983
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000149485-FADS1/tissue/colon#imid_11195629
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000149485-FADS1/tissue/liver#imid_11195638
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000149485-FADS1/tissue/kidney#imid_11195639
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for FADS1 IHC & IF
🧪Run adipose tissue first and look for staining in adipocytes (HPA: adipocytes Medium). Use peripheral nerve in soft tissue as the negative tissue (HPA: peripheral nerve Not detected); on the positive slide, non-adipocyte cells with only background staining can serve as provisional internal negatives, since their FADS1 status is not specified (HPA: adipose tissue row).
Positive control tissue: Adipose tissue (Adipocytes, HPA Medium)
Negative control tissue: Soft tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for FADS1; derive a cell-line control from the positive tissue's cell type (Adipocytes) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only) and concentration-matched rabbit IgG isotype controls for the catalog antibody (selected-SKU IHC caption: rabbit primary), plus a FADS1 knockout specimen or validated peptide-block control where available. Quench endogenous peroxidase for DAB detection and assess background around adipocyte lipid spaces (selected-SKU IHC caption: HRP/DAB; HPA: adipocytes Medium).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU paraffin-section caption does not state a fixative (selected-SKU IHC caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 was used for the pictured IHC section, but its necessity has not been established by the supplied evidence (selected-SKU IHC caption: heat-mediated EDTA retrieval). Neither frozen sections nor IF can be judged easier from these sources (HPA subcellular: no ICC-IF image cell lines); in adipose sections, score staining in the thin cytoplasm around lipid spaces rather than within the clear spaces (HPA: adipocytes Medium; standard adipose histology).
HPA tissue IHC evidence for FADS1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Medium | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Adipocytes | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Soft tissue | Peripheral nerve | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced FADS1 IHC Tips
Troubleshoot FADS1 staining in paraffin sections using the documented IHC conditions, protein topology, and tissue staining evidence.
How should I retrieve FADS1 when paraffin-section staining is weak?
Start with heat-mediated retrieval in EDTA pH 8.0 (datasheet M02535). That condition was used for the catalog antibody on a paraffin-embedded human liver cancer section, followed by 1:50 primary antibody overnight at 4°C (datasheet M02535). If staining remains weak, adjust heating duration in small increments while holding the buffer and detection conditions constant, and inspect morphology after each change (standard IHC practice). Compare each run with a concurrently stained reference section and a no-primary control so stronger signal can be assessed alongside tissue damage and background (standard IHC practice).
Could fixation explain variable FADS1 staining between paraffin sections?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state its fixative (datasheet M02535). Record the fixative, fixation duration, processing history, section age, and retrieval run for each specimen before comparing staining intensity (standard IHC practice). For a controlled comparison, process matched sections consistently and begin with heat-mediated EDTA pH 8.0 retrieval, the documented condition for this antibody (datasheet M02535). If results differ, assess morphology and a no-primary control alongside the FADS1 stain; these checks can reveal processing or detection problems without assigning the difference to a FADS1-specific fixation effect (standard IHC practice).
What staining pattern fits FADS1, and which patterns need checking?
Expect predominantly cytoplasmic staining at light-microscope resolution: FADS1 is annotated at the endoplasmic reticulum membrane and mitochondrion, while tissue IHC reports general cytoplasmic expression (UniProt O60427 subcellular location; HPA: general cytoplasmic expression). Its 4 transmembrane segments support a membrane-associated interpretation, but chromogenic staining alone cannot assign signal to either organelle (UniProt O60427 topology; standard IHC practice). Review staining within intact cells against the counterstain and tissue architecture, then compare a no-primary control for diffuse deposit or pigment (standard IHC practice). Treat a predominantly nuclear pattern as a reason to check antibody specificity and detection background before assigning it to FADS1 (UniProt O60427 subcellular location; standard IHC practice).
How could FADS1 isoforms or epitope position affect section staining?
FADS1 has 2 annotated isoforms, so confirm which sequence the catalog antibody recognizes before interpreting discordant samples (UniProt O60427 isoforms). The supplied evidence does not identify its epitope or establish isoform-specific recognition (datasheet M02535; UniProt O60427 isoforms). For epitope-access planning, the annotated cytoplasmic regions are residues 1–121, 171–267, and 327–444, whereas the luminal loops are 143–145 and 289–305 (UniProt O60427 topology). If an epitope sequence becomes available, map it to those regions and the isoforms, then evaluate retrieval changes with matched sections rather than attributing a weak stain to splicing alone (UniProt O60427 topology; standard IHC practice).
How can IF help assess an ambiguous FADS1 IHC pattern?
Use IF as a separate validation experiment, pairing FADS1 with a marker for the expected cell population; HPA reports medium staining in adrenal glandular cells and adipocytes (HPA: adrenal gland and adipose tissue). Select a FADS1 fluorophore in a channel with low measured tissue autofluorescence, and include single-label and no-primary controls when assessing multiplex signal (standard IF practice). Permeabilisation should be tested against the mapped epitope: FADS1 has cytoplasmic regions and short luminal loops across 4 transmembrane segments, while this antibody’s epitope is unspecified (UniProt O60427 topology; datasheet M02535). Judge cellular overlap and intracellular distribution separately; IF colocalisation alone does not establish antibody specificity (standard IF practice).
How do I reduce diffuse or granular background in FADS1 IHC?
First inspect a no-primary control and the counterstained section to distinguish reagent background, pigment, and tissue structure from specific chromogen deposit (standard IHC practice). The documented paraffin-section method used 10% goat serum blocking, 1:50 rabbit primary overnight at 4°C, and a peroxidase-linked secondary before DAB development (datasheet M02535). Include an endogenous peroxidase block and keep DAB development consistent across comparison sections; these are general chromogenic IHC controls (standard IHC practice). If background persists, titrate the primary around the documented condition and review washing and secondary-only staining while retaining EDTA pH 8.0 retrieval as the starting point (datasheet M02535; standard IHC practice).
How should I score FADS1 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and tissue area before scoring, and exclude folds, edges, and necrotic regions using the counterstain and morphology (standard IHC practice). For intact cells, record the percentage positive and intensity categories consistently, then calculate an H-score on the 0–300 scale if intensity comparisons are needed (standard IHC practice). Alternatively, report positive-cell density per mm² of evaluable tissue, normalised to the same annotated compartment across sections (standard IHC practice). Keep acquisition and DAB development consistent, and interpret intensity cautiously because HPA reports low consistency between FADS1 antibody staining and RNA expression (standard IHC practice; HPA: approved with low staining–RNA consistency).
When is an apparent FADS1-positive stain likely to be artefact?
A convincing result should occur within intact, identifiable cells and show a predominantly cytoplasmic pattern compatible with FADS1’s endoplasmic reticulum membrane and mitochondrial annotations (HPA: general cytoplasmic expression; UniProt O60427 subcellular location). Assess the cell type against tissue context: HPA reports medium staining in adipocytes and adrenal glandular cells, while peripheral nerve in soft tissue was not detected (HPA: tissue IHC). Strong nuclear-only signal, tissue-edge staining, necrotic deposits, or staining reproduced by a no-primary control warrants investigation before scoring (UniProt O60427 subcellular location; standard IHC practice). Check endogenous peroxidase and pigment where appropriate, and avoid treating staining intensity alone as proof of FADS1 abundance given HPA’s reported low staining–RNA consistency (standard IHC practice; HPA: approved with low staining–RNA consistency).
Boster reagents
Best FADS1 / Acyl-CoA (8-3)-desaturase IHC Antibodies
Anti-FADS1 IHC images cover human paraffin sections (M02535 and A02535-1 IHC captions); IF images cover human paraffin sections (A02535-1 IF captions).
Real IHC data
Anti-FADS1 Rabbit Monoclonal Antibody
Cat # M02535
Real IHC data
Anti-FADS1 Antibody ®
Cat # A02535-1
M02535 has IHC images from human liver, liver cancer and thyroid cancer paraffin sections; its listed reactivity includes human, mouse and rat (M02535 IHC captions; catalog reactivity). A02535-1 has IHC images from human liver, lung and ovarian cancer paraffin sections and IF images from human liver and ovarian cancer paraffin sections (A02535-1 IHC and IF captions).
Which to pick: For tissue IHC, M02535 is a rabbit monoclonal used at 1:50, while A02535-1 was used at 2 μg/ml; each SKU’s human paraffin-section IHC caption documents EDTA retrieval at pH 8.0 (catalog; respective IHC captions). For IF, choose A02535-1 if an IF tissue image is useful; for ICC, M02535 lists that application, though its supplied images are IHC only (A02535-1 IF captions; M02535 applications and image list). For mouse or rat work, M02535 lists those species, but its supplied IHC images show human sections only; neither SKU’s IHC caption reports the fixative (M02535 reactivity and IHC captions; A02535-1 IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O60427 (FADS1_HUMAN, Acyl-CoA (8-3)-desaturase).
- Human Protein Atlas. FADS1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. FADS1 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. FADS1 antibody validation summary (1 antibodies).
- Fatty Acid Desaturase 1 Knockdown Promotes Wound Healing and Functional Recovery of the Corneal Epithelium in Diabetes. Investigative ophthalmology & visual science 2025 — PMC12136103.
- Reduced Expression of FADS1 Predicts Worse Prognosis in Non-Small-Cell Lung Cancer. Journal of Cancer 2016 — PMC4934030.
- SPP1⁺ macrophage-FADS1⁺ tumor cell crosstalk via the PDGFB-PDGFRB axis drives liver metastasis in colorectal cancer. Translational oncology 2026 — PMC12905685.
- Elevation of fatty acid desaturase 2 in esophageal adenocarcinoma increases polyunsaturated lipids and may exacerbate bile acid-induced DNA damage. Clinical and translational medicine 2022 — PMC9099135.
- PubMed PMID:10601301 — UniProt-cited evidence.
- PubMed PMID:10769175 — UniProt-cited evidence.
- PubMed PMID:10860662 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for FADS1 (Acyl-CoA (8-3)-desaturase). Expected localisation Cytoplasmic tissue staining (HPA tissue IHC); ER and mitochondrion (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M02535). Validated IHC antibody: M02535 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Soft tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet M02535); 2. Fixation: Image fixative and duration unreported (datasheet M02535); 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 M02535); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M02535); 8. Primary antibody: Rabbit monoclonal (clone 26F55) anti-FADS1, 1:50 (datasheet M02535); 9. Primary incubation: Overnight at 4 °C (datasheet M02535). Watch for: Fixation: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Antibody staining has low agreement with RNA expression (HPA tissue IHC); Isoform / epitope: Two isoforms; epitope coverage is unspecified (UniProt); Regulation: Expression regulation not specified (UniProt). Evidence: UniProt O60427, HPA tissue IHC · Approved, HPA ICC-IF · Membrane, Datasheet M02535, PMC12136103, PMC4934030. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/FADS1/immunohistochemistry-ihc-guide.