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ASCL1 / Achaete-scute homolog 1 · IHC design guide
Design Immunohistochemistry for ASCL1
Plan ASCL1 IHC on paraffin sections using the catalog antibody’s documented staining conditions (datasheet A03023-2). Compare CNS staining with HPA tissue patterns while interpreting cytoplasmic signal alongside ASCL1’s annotated nuclear location (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ASCL1 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 | CNS cytoplasm observed (HPA tissue IHC); nucleus annotated (UniProt) | |
| Staining pattern | Cytoplasmic staining in CNS glia and cerebellar processes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A03023-2) | |
| Positive control | Cerebellum+3 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 sections. (standard IHC practice; not target-specific) | |
| Caveat | Cytoplasmic tissue staining (HPA tissue IHC) differs from the annotated nuclear location (UniProt) | |
| Regulation | Linked to early neural differentiation (UniProt) | |
| Isoform / epitope | No annotated isoforms or processing to alter the epitope map (UniProt) |
Section 1
Recommended ASCL1 IHC & IF Protocols
The catalog antibody protocol uses EDTA pH 8.0 retrieval (datasheet A03023-2). The published IHC protocols below report additional ASCL1 staining conditions (PMC8078053; PMC10855250; PMC7779202).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A03023-2) |
| Fixation | Image fixative and duration unreported (datasheet A03023-2); 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 A03023-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03023-2) |
| Primary antibody | Rabbit anti-ASCL1, 2-5 μg/ml (datasheet A03023-2) |
| Primary incubation | Overnight at 4 °C (datasheet A03023-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A03023-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ASCL1-positive staining in processes in granular layer of cerebellum (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in CNS. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet A03023-2); sodium citrate pH 6.0 is a published alternative using a different antibody (PMC10855250).
Section 2
What Is the Expected ASCL1 Staining Pattern?
ASCL1 is a nuclear transcription factor without a transmembrane segment (UniProt P50553: nucleus, function, topology). In tissue IHC, HPA reports cytoplasmic staining in CNS cells, including glial cells in cerebral cortex and hippocampus and processes in the cerebellar granular layer (HPA: tissue IHC). HPA rates the tissue profile Enhanced for consistency with RNA expression (HPA: reliability). Read nuclear and cytoplasmic signals in light of that compartment difference.
| Strong staining in cortical or hippocampal glial cells, or cerebellar granular-layer processes. | These match HPA's High tissue IHC observations; HPA describes the CNS profile as cytoplasmic (HPA: tissue IHC). Record cell type and compartment separately, because UniProt places ASCL1 in the nucleus (UniProt P50553: subcellular location). |
| Predominantly extracellular, surface-like, or uniformly distributed staining, without the reported cellular pattern. | That compartment does not fit UniProt's nuclear location or HPA's reported CNS cytoplasmic staining (UniProt P50553: subcellular location; HPA: tissue IHC). Treat it as a possible artefact; inspect morphology and detection controls before scoring. |
| Strong signal in a cell type HPA lists as not detected, such as adipocytes in adipose tissue. | The result conflicts with that HPA tissue observation (HPA: adipose-tissue adipocytes, Not detected). Consider antibody cross-reactivity or endogenous chromogen activity; a single unexpected positive does not establish ASCL1 expression (standard IHC practice). |
| Diffuse chromogen across cells and surrounding tissue, obscuring cellular boundaries. | This cannot be assigned confidently to the HPA-reported glial cells or granular-layer processes (HPA: tissue IHC). Uneven blocking, retained detection reagent, or endogenous enzyme activity can produce background in chromogenic IHC (standard IHC practice). |
| No staining in a section expected to show HPA's High CNS pattern. | Cerebral cortex, hippocampus, and cerebellum have High observations in specified cells or processes (HPA: tissue IHC). First check that those structures are present, then check the run controls and IHC workflow; HPA's observations do not guarantee every section will stain. |
💡Expected ASCL1 appearanceCall a result consistent when defined cortical or hippocampal glial cells, or cerebellar granular-layer processes, show the reported High staining (HPA: tissue IHC); diffuse extracellular colour or similarly strong staining in HPA-listed negative cell types warrants investigation (HPA: tissue IHC; standard IHC practice).
| Compartment evidence | UniProt assigns ASCL1 to the nucleus; HPA tissue IHC describes cytoplasmic CNS staining, while HPA ICC-IF places it mainly in nucleoplasm with additional cytosol (UniProt P50553: location; HPA: tissue IHC and ICC-IF). Report the observed compartment rather than collapsing these assays into one rule. |
| Cell and tissue selection | HPA reports High staining in cortical and hippocampal glial cells and cerebellar granular-layer processes, but Medium staining in caudate glial cells (HPA: tissue IHC). Compare like cell types when judging intensity; whole-section colour can hide that distinction. |
| Validation scope | The tissue profile has Enhanced reliability, and HPA029217 has Enhanced IHC status (HPA: tissue reliability and antibody validation). Those designations support the reported pattern; they do not resolve whether an unexpected compartment or cell type is specific. |
| Protein features and retrieval | UniProt lists no signal peptide, propeptide, transmembrane segment, or isoforms, and identifies a bHLH domain at residues 118–170 (UniProt P50553: processing, topology, isoforms, domains). The supplied sources give no epitope or ASCL1-specific retrieval response; use the catalog antibody's IHC-P guidance for setup. |
| IF/ICC Q&A | What should IF/ICC show? Mainly nucleoplasmic signal with additional cytosolic signal (HPA: ICC-IF, approved locations). That cellular localisation is useful context, but it does not replace HPA's tissue IHC observations or define an IF protocol. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in cortical or hippocampal glial cells. | The expected cells may be absent from the field, or the IHC run may have failed; both tissues have High glial-cell observations (HPA: tissue IHC). | Confirm cell identity and section quality, then review the run control, retrieval, antibody dilution, and detection steps against the catalog antibody's IHC-P instructions (standard IHC practice). |
| Only diffuse colour is visible. | Nonspecific binding or endogenous enzyme activity can obscure cellular staining in chromogenic IHC (standard IHC practice). | Compare an appropriate detection control, review blocking and washes, and score only resolved cells or processes; HPA's CNS observations are cell-specific (HPA: tissue IHC; standard IHC practice). |
| Signal appears chiefly on cell surfaces or in extracellular material. | That distribution conflicts with UniProt's nuclear assignment and HPA's cellular CNS observations (UniProt P50553: location; HPA: tissue IHC). | Check the counterstain and morphology, then compare controls and the reported cellular pattern before calling ASCL1 positive (standard IHC practice; HPA: tissue IHC). |
| Strong staining appears in HPA-listed negative cells. | Cross-reactivity or endogenous chromogenic activity is possible; HPA reports no detection in adipose-tissue adipocytes and several other specified cell types (HPA: tissue IHC). | Verify the cell type and detection controls. Treat the finding as unresolved unless it is reproducible with appropriate independent support (standard IHC practice). |
| Nuclear signal is seen, but the reported cytoplasmic CNS pattern is weak. | The sources differ by assay: UniProt assigns nuclear location, HPA ICC-IF favours nucleoplasm, and HPA tissue IHC reports cytoplasmic CNS expression (UniProt P50553: location; HPA: ICC-IF and tissue IHC). | Document nuclear and cytoplasmic scores separately. Compare the correct cell types and IHC controls; do not infer an ASCL1-specific fixation or retrieval effect from these sources. |
| Caudate staining looks weaker than cortical or hippocampal staining. | HPA reports Medium in caudate glial cells versus High in cortical and hippocampal glial cells (HPA: tissue IHC). | Compare matched cell types and controls before adjusting the assay. This difference alone is consistent with the reported tissue pattern (HPA: tissue IHC). |
Experiment evidence
IHC & IF images showing ASCL1 staining
A03023-2 · IHCIHC analysis of ASCL1 using anti-ASCL1 antibody (A03023-2). ASCL1 was detected in a paraffin-embedded section of human lung cancer tissue. H
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000139352-ASCL1/tissue/cerebral+cortex#imid_7527894
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000139352-ASCL1/tissue/colon#imid_7513542
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000139352-ASCL1/tissue/liver#imid_7513543
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000139352-ASCL1/tissue/kidney#imid_7513536
HPA · ICC-IF HAP1Human Protein Atlas immunofluorescence, HAP1, antibody HPA076307; green = ASCL1, blue = nucleus, red = microtubules.
HPA · ICC-IF HAP1Human Protein Atlas immunofluorescence, HAP1, antibody HPA076307; green = ASCL1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ASCL1 IHC & IF
🧪Run cerebral cortex first and look for staining in glial cells (HPA: High in cerebral cortex glial cells). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); on the positive slide, cells without nuclear staining provide an internal background reference (UniProt P50553: nuclear localization).
Positive control tissue: Cerebellum (Processes in granular layer, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ASCL1 in HAP1, SH-SY5Y, U2OS, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and a concentration-matched rabbit IgG isotype control (selected-SKU IHC caption: rabbit primary antibody; standard IHC practice). Use ASCL1 knockout tissue as a biological negative where available, and quench endogenous peroxidase before chromogenic detection in the positive tissue (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected A03023-2 paraffin-section caption does not state the fixative (selected-SKU IHC caption). The caption reports heat-mediated retrieval in EDTA at pH 8.0, but does not establish that retrieval is required under every condition (selected-SKU IHC caption). The evidence does not establish whether frozen sections or IF are easier; cerebral cortex lipofuscin can produce IF autofluorescence, so assess fluorescence against a no-primary control (standard IF practice).
HPA tissue IHC evidence for ASCL1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 |
|---|---|---|---|---|
| Cerebellum | Processes in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
| Hippocampus | Glial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | 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 | Endocrine 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 ASCL1 IHC Tips
Troubleshoot ASCL1 chromogenic IHC by checking retrieval, tissue processing, compartment-specific staining and controls before comparing scores across sections.
What retrieval should I try first if ASCL1 staining is weak?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A03023-2). The catalog antibody detected ASCL1 after this retrieval at 2 μg/ml with overnight incubation at 4°C (datasheet A03023-2). If staining remains weak, adjust heating duration or temperature in small steps while keeping a reference section in each run (standard IHC practice). Excessive retrieval can damage morphology or increase diffuse staining, so compare signal with tissue preservation and a no-primary control (standard IHC practice). Score nuclear signal separately from cytoplasmic signal because ASCL1 is nuclear by UniProt annotation, while additional cytosolic localisation is reported by HPA (UniProt P50553; HPA subcellular).
Could fixation explain inconsistent ASCL1 staining between paraffin blocks?
Target-specific sensitivity to fixation is unknown: the catalog image describes a paraffin section but does not state its fixative (datasheet A03023-2). Record the fixative and fixation duration for each block, then compare sections processed with the same EDTA pH 8.0 retrieval and detection run (datasheet A03023-2; standard IHC practice). Differences in fixation can alter morphology and antigen accessibility in IHC generally, but they do not establish an ASCL1-specific effect here (standard IHC practice). Use the reported 2 μg/ml overnight primary incubation as a starting reference when investigating block-to-block variation (datasheet A03023-2). Judge any adjustment against preserved cellular detail, a positive reference section and a no-primary control (standard IHC practice).
How should I assess ASCL1 staining outside the nucleus?
Assess nuclear staining first because ASCL1 is annotated as nuclear and functions as a DNA-binding transcription factor (UniProt P50553). HPA also reports approved nucleoplasmic and additional cytosolic localisation, so cytoplasmic signal deserves separate review rather than automatic rejection (HPA subcellular). In tissue IHC, HPA describes cytoplasmic expression in the CNS, including high staining in cerebellar granular-layer processes and cortical glial cells (HPA tissue IHC). Record nuclear and cytoplasmic intensity independently at each site, with the same 0–3 intensity scale across sections (standard IHC practice). If diffuse staining obscures nuclei, review retrieval, primary concentration and no-primary controls before assigning ASCL1 positivity (standard IHC practice).
Could an isoform or epitope difference explain discordant ASCL1 IHC?
The supplied UniProt record lists 0 annotated isoforms and a 236-residue ASCL1 chain, so it supplies no isoform-specific staining prediction (UniProt P50553). Its bHLH domain spans residues 118–170, and an N6-acetyllysine is annotated at residue 156 (UniProt P50553). The catalog caption does not map the antibody epitope, so neither feature establishes whether fixation, retrieval or acetylation affects recognition (datasheet A03023-2; UniProt P50553). Compare discrepant samples under the same EDTA pH 8.0 retrieval and antibody incubation conditions before attributing differences to epitope availability (datasheet A03023-2; standard IHC practice). If an independent antibody is available, compare its staining and documented epitope with the catalog result (standard IHC practice).
How can I investigate ASCL1 localisation by multiplex IF?
Use IF as a separate validation experiment: the catalog example establishes paraffin-section chromogenic IHC, not IF performance for this antibody (datasheet A03023-2). Pair ASCL1 with a marker identifying the expected cell population, such as glial cells in the relevant CNS regions, and include a nuclear counterstain (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores, favouring a longer-wavelength ASCL1 channel when tissue autofluorescence is prominent, and inspect single-stain controls (standard IF practice). Because ASCL1 is intracellular and lacks a transmembrane segment, permeabilise fixed cells sufficiently to assess the nuclear compartment while checking morphology (UniProt P50553; standard IF practice). HPA reports mainly nucleoplasmic and additional cytosolic localisation, which can guide compartment-by-compartment comparison with IHC (HPA subcellular).
How do I reduce diffuse or brown background in ASCL1 IHC?
First compare the stained section with a no-primary control to distinguish primary-associated signal from detection background (standard IHC practice). The catalog example used 10% goat serum block, a peroxidase-conjugated secondary for 30 minutes at 37°C, and DAB development (datasheet A03023-2). Include an endogenous peroxidase block before HRP detection and optimise DAB development time if brown deposit appears in both test and no-primary sections (standard IHC practice). Check that sections are adequately washed and that the primary concentration has not exceeded the useful range; 2 μg/ml is the catalog example, not a universal optimum (datasheet A03023-2; standard IHC practice). Compare background in intact tissue away from folds, edges and damaged areas (standard IHC practice).
What is a defensible way to quantify ASCL1-positive cells? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue region and scoring compartment before counting, because UniProt assigns ASCL1 to the nucleus while HPA also reports cytosolic localisation (UniProt P50553; HPA subcellular). For nuclear IHC, report the percentage of positive viable cells and an H-score using intensity grades 0–3, with a possible H-score range of 0–300 (standard IHC practice). If cell abundance varies by area, also report positive-cell density per mm² of analysed viable tissue (standard IHC practice). Normalise cell counts to the relevant cell population or measured viable area, and keep thresholds and imaging settings consistent across cases (standard IHC practice). Report cytoplasmic staining separately so it does not inflate a nuclear score (standard IHC practice).
How can I distinguish true ASCL1 positivity from artefact?
A convincing result has reproducible staining in intact cells, with nuclear signal supported by ASCL1's annotated nuclear localisation (UniProt P50553). Additional cytosolic signal is possible, but HPA's CNS tissue pattern includes cytoplasmic staining, so interpret that compartment by tissue and cell type (HPA tissue IHC; HPA subcellular). Compare suspect staining with the no-primary control and inspect edges, folds and necrotic regions before scoring; endogenous peroxidase can also produce misleading DAB signal (standard IHC practice). The catalog image documents ASCL1 detection in a paraffin section of human lung cancer after EDTA pH 8.0 retrieval, without establishing that every stained compartment is specific (datasheet A03023-2). Resolve discordant patterns using matched controls and independently documented localisation (standard IHC practice; UniProt P50553; HPA subcellular).
Boster reagents
Best ASCL1 / Achaete-scute homolog 1 IHC Antibodies
A03023-2 has real IHC data from a paraffin-embedded human lung cancer section (A03023-2 IHC caption). Its listed reactivity covers human, mouse and rat (catalog reactivity); no IF data are supplied (catalog IF figures).
Real IHC data
Anti-ASCL1 Antibody ®
Cat # A03023-2
A03023-2 is the only SKU shown and is listed for IHC (catalog applications). Its own figure documents staining in a paraffin-embedded human lung cancer section; the fixative is unreported (A03023-2 IHC caption).
Which to pick: For paraffin-section IHC, choose A03023-2 at the listed 2–5 μg/ml; its figure used 2 μg/ml after heat retrieval in EDTA, pH 8.0 (catalog IHC dilution; A03023-2 IHC caption). No IF/ICC SKU is supported here because A03023-2 has neither IF/ICC in its application list nor an IF figure (catalog applications; catalog IF figures). For cross-species planning, A03023-2 lists human, mouse and rat reactivity, but the supplied IHC dilution and figure cover human only (catalog reactivity; catalog IHC dilution; A03023-2 IHC caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P50553 (ASCL1_HUMAN, Achaete-scute homolog 1).
- Human Protein Atlas. ASCL1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. ASCL1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. ASCL1 antibody validation summary (2 antibodies).
- A comparison of adult rhabdomyosarcoma and high-grade neuroendocrine carcinoma of the urinary bladder reveals novel PPP1R12A fusions in rhabdomyosarcoma. Human pathology 2019 — PMC8078053.
- Postnatal Exposure to the Endocrine Disruptor Dichlorodiphenyltrichloroethane Affects Adrenomedullary Chromaffin Cell Physiology and Alters the Balance of Mechanisms Underlying Cell Renewal. International journal of molecular sciences 2024 — PMC10855250.
- Clinicopathological features and prognostic implications of ASCL1 expression in surgically resected small cell lung cancer. Thoracic cancer 2021 — PMC7779202.
- Pulmonary Neuroendocrine Cells and Small Cell Lung Carcinoma: Immunohistochemical Study Focusing on Mechanisms of Neuroendocrine Differentiation. Acta histochemica et cytochemica 2022 — PMC9253501.
- PubMed PMID:8390674 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ASCL1 (Achaete-scute homolog 1). Expected localisation CNS cytoplasm observed (HPA tissue IHC); nucleus annotated (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03023-2). Validated IHC antibody: A03023-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Cerebellum (Processes in granular layer); 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 A03023-2); 2. Fixation: Image fixative and duration unreported (datasheet A03023-2); 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 A03023-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03023-2); 8. Primary antibody: Rabbit anti-ASCL1, 2-5 μg/ml (datasheet A03023-2); 9. Primary incubation: Overnight at 4 °C (datasheet A03023-2). Watch for: Fixation: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Cytoplasmic tissue staining (HPA tissue IHC) differs from the annotated nuclear location (UniProt); Isoform / epitope: No annotated isoforms or processing to alter the epitope map (UniProt); Regulation: Linked to early neural differentiation (UniProt). Evidence: UniProt P50553, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A03023-2, PMC8078053, PMC10855250. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ASCL1/immunohistochemistry-ihc-guide.