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ALDH1A1 / Aldehyde dehydrogenase 1A1 · IHC design guide
Design Immunohistochemistry for ALDH1A1
Plan ALDH1A1 paraffin IHC around cytoplasmic staining in selected tissues (HPA tissue IHC). The guide covers a catalog antibody's IHC dilution of 0.5–1 μg/ml (datasheet A01392) and tissue controls based on reported staining (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ALDH1A1 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 staining in selected tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic signal in selected cells, including glandular cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A01392) | |
| Positive control | Epididymis+4 more · see all | |
| Negative control | Adrenal gland+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Antibody staining and RNA show medium consistency (HPA tissue IHC) | |
| Regulation | Regulation is not specified (UniProt) | |
| Isoform / epitope | 0 annotated isoforms; mature chain spans 2–501 (UniProt) |
Section 1
Recommended ALDH1A1 IHC & IF Protocols
The catalog antibody protocol is paired with published ALDH1A1 IHC methods for pancreatic cancer (PMC3135572) and colorectal tumors and liver metastases (PMC6181398).
| Sample | Paraffin-embedded human renal cancer tissues; fixative not specified (datasheet A01392) |
| Fixation | Image fixative and duration unreported (datasheet A01392); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A01392) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01392) |
| Primary antibody | Rabbit anti-ALDH1A1, 0.5-1μg/ml (datasheet A01392) |
| Primary incubation | Overnight at 4 °C (datasheet A01392) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01392) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ALDH1A1-positive staining in glandular cells of epididymis (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in selected tissues. No signal in the no-primary control. |
💡Decision noteStart with heat retrieval at pH 6, as specified for the catalog antibody (datasheet A01392) and used in both published protocols (PMC3135572; PMC6181398).
Section 2
What Is the Expected ALDH1A1 Staining Pattern?
ALDH1A1 is a cytosolic protein with no transmembrane segment (UniProt P00352: subcellular location and topology). In paraffin section IHC, expect cytoplasmic staining in selected cells, especially epididymal and stomach glandular cells, with lower staining in several other listed tissues (HPA: tissue IHC). HPA rates the tissue profile Enhanced, while reporting medium consistency between antibody staining and RNA expression (HPA: tissue IHC reliability).
| Strong cytoplasmic staining in epididymal or stomach glandular cells, with cell boundaries still discernible. | This fits the reported High protein staining in those cell types and the cytosolic location (HPA: tissue IHC; HPA: subcellular ICC-IF). Judge intensity against controls processed in the same IHC run (general IHC practice). |
| Predominantly nuclear, membrane outlined, or extracellular staining, especially without cytoplasmic signal. | These compartments conflict with the reported cytosolic location and lack of a transmembrane segment (HPA: subcellular ICC-IF; UniProt P00352: topology). Consider nonspecific staining or a detection artefact; compartment alone cannot identify its cause (general IHC practice). |
| Prominent staining in a cell type reported as Not detected, such as adrenal glandular cells. | That result disagrees with the reference cell type, although HPA's category is an observation, not a guarantee for every specimen (HPA: adrenal gland IHC). Check for cross-reactivity or endogenous chromogenic activity using appropriate assay controls (general IHC practice). |
| Uniform colour across cells and surrounding tissue, obscuring cell boundaries. | A nonselective deposit is difficult to reconcile with HPA's cytoplasmic expression in selected tissues (HPA: tissue IHC profile). Review blocking, washes and chromogen controls before assigning any of that colour to ALDH1A1 (general IHC practice). |
| No cytoplasmic signal in an epididymis or stomach section expected to be positive. | HPA reports High staining in the glandular cells of both tissues (HPA: epididymis and stomach IHC). First confirm that the relevant cells are present, then check assay controls and detection steps; a negative slide alone cannot establish absent protein (general IHC practice). |
💡Expected ALDH1A1 appearanceCall the IHC result positive when glandular cells show clear, predominantly cytoplasmic staining, strongest in epididymis or stomach reference sections (HPA: High in epididymis and stomach glandular cells; UniProt P00352: cytosol); isolated nuclear colour or widespread colour unrelated to cell type warrants artefact checks (general IHC practice).
| Reference tissue and cell type | HPA reports High staining in epididymis and stomach glandular cells, but Medium staining in hepatocytes and several other listed cells (HPA: tissue IHC). Compare like cell types; liver's enhanced RNA specificity does not imply the strongest protein IHC signal (HPA: tissue IHC and RNA specificity). |
| Intracellular location and topology | Cytosol is the main location in ICC-IF, and UniProt lists cytosol and axon with no transmembrane segment (HPA: subcellular ICC-IF; UniProt P00352: location and topology). Interpret membrane outlined IHC staining cautiously. |
| Antibody validation | HPA lists Enhanced IHC validation for HPA002123 and CAB020690; Enhanced means the pattern is reproduced by independent antibodies or orthogonal data (HPA: antibody validation). This supports the reference pattern, but a new run still needs appropriate controls (general IHC practice). |
| IF/ICC: what pattern should I expect? | Expect cytosolic fluorescence: HPA's ICC-IF summary says cytosol and lists HPA002123 as Supported for ICC (HPA: subcellular ICC-IF; HPA: antibody validation). This answers localisation only; the IF/ICC guide handles its assay procedure. |
| Protein processing and modifications | UniProt reports no signal peptide or propeptide and lists a chain spanning residues 2–501, plus modified residues (UniProt P00352: processing and modifications). These annotations provide no target-specific prediction of antigen retrieval or fixation sensitivity. |
| Situation | Likely cause | Next action |
|---|---|---|
| The positive reference section is blank. | The expected glandular cells may be absent from the section, or an IHC reagent or detection step may have failed (HPA: High in epididymis and stomach glandular cells; general IHC practice). | Confirm the relevant cells on the counterstained section, then review the run's positive control and primary antibody and detection steps (general IHC practice). |
| Signal appears mainly nuclear or at cell borders. | The distribution conflicts with ALDH1A1's cytosolic assignment and lack of a transmembrane segment (HPA: subcellular ICC-IF; UniProt P00352: topology). | Compare with a cytoplasmic positive reference and a primary antibody omission control; reassess specificity before scoring it as ALDH1A1 (general IHC practice). |
| A reported negative cell type stains strongly. | Cross-reactivity or endogenous detection activity is possible; HPA reports Not detected for adrenal glandular cells, among other specified cell types (HPA: tissue IHC; general IHC practice). | Check cell identity and compare primary antibody omission and detection controls; report the discrepancy rather than treating the HPA category as an absolute rule (general IHC practice). |
| Brown deposit or diffuse colour obscures the cells. | Background from chromogenic detection or insufficient blocking or washing can obscure selective cytoplasmic staining (general IHC practice; HPA: tissue IHC profile). | Inspect a primary antibody omission control, check the relevant endogenous enzyme block, and review wash and chromogen development steps (general IHC practice). |
| Liver staining is weaker than stomach staining. | This can match the reference: hepatocytes are Medium and stomach glandular cells are High by IHC (HPA: tissue IHC). | Score the observed cells against their tissue specific reference level and same run controls, rather than expecting equal intensity (HPA: tissue IHC; general IHC practice). |
| ICC-IF fluorescence seems widespread despite a plausible positive signal. | HPA places ALDH1A1 in the cytosol, so fluorescence outside cell boundaries or in an unrelated compartment needs evaluation (HPA: subcellular ICC-IF). | Check the cellular outline and compare secondary only and background controls before assigning a cytosolic pattern; use the separate IF/ICC guide for procedure (general IF practice). |
Experiment evidence
IHC & IF images showing ALDH1A1 staining
A01392 · IHCIHC analysis of ALDH1A1 using anti-ALDH1A1 antibody (A01392). ALDH1A1 was detected in paraffin-embedded section of human renal cancer tissue
A01392 · IHCIHC analysis of ALDH1A1 using anti-ALDH1A1 antibody (A01392). ALDH1A1 was detected in paraffin-embedded section of human renal cancer tissue
A01392 · IFIF analysis of ALDH1A1 using anti-ALDH1A1 antibody (A01392). ALDH1A1 was detected in immunocytochemical section of A431 cell. Enzyme antigen
M01392-2 · IHCIHC analysis of ALDH1A1 using anti-ALDH1A1 antibody (M01392-2). ALDH1A1 was detected in a paraffin-embedded section of human gall bladder ad
M01392-2 · IHCIHC analysis of ALDH1A1 using anti-ALDH1A1 antibody (M01392-2). ALDH1A1 was detected in a paraffin-embedded section of human lymphadenoma ti
M01392-2 · IFIF analysis of ALDH1A1 using anti-ALDH1A1 antibody (M01392-2). ALDH1A1 was detected in an immunocytochemical section of A549 cells. Enzyme a
PA1671 · IHCIHC analysis of ALDH1A1 using anti-ALDH1A1 antibody (PA1671). ALDH1A1 was detected in a paraffin-embedded section of human lung cancer tissu
PA1671 · IFIF analysis of ALDH1A1 using anti-ALDH1A1 antibody (PA1671). ALDH1A1 was detected in an immunocytochemical section of A549 cells. Enzyme ant
M01392-3 · IHCMouselung was stained with anti-ALDH1A1 rabbit antibody
M01392-3 · IHCRatlung was stained with anti-ALDH1A1 rabbit antibody
M01392-1 · IHCImmunohistochemical analysis of paraffin-embedded human liver cancer, using ALDH1A1 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000165092-ALDH1A1/tissue/cerebral+cortex#imid_5585756
HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000165092-ALDH1A1/tissue/stomach+2#imid_5585640
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000165092-ALDH1A1/tissue/colon#imid_5585674
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000165092-ALDH1A1/tissue/liver#imid_5585691
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA002123; green = ALDH1A1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA002123; green = ALDH1A1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ALDH1A1 IHC & IF
🧪Run epididymis first: glandular cells should stain (HPA: High in epididymis glandular cells). Use adrenal glandular cells as a negative tissue (HPA: Not detected in adrenal glandular cells); on the positive slide, assess unstained neighboring cells as a background reference without assuming their ALDH1A1 status.
Positive control tissue: Epididymis (Glandular cells, HPA High)
Negative control tissue: Adrenal gland (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ALDH1A1 in A-549, Hep-G2, BJ hTERT+ SV40 Large T+, BJ hTERT+ SV40 Large T+ RasG12V, BJ [Human fibroblast], BJ1-hTERT, with annotated localisation: Cytosol (enhanced) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) control, a matched rabbit IgG isotype control appropriate to the primary antibody’s clonality (caption: rabbit anti-ALDH1A1), and an ALDH1A1 knockout control where available. Check endogenous peroxidase and biotin background in the epididymis section when using the caption’s biotin-based DAB detection (caption: biotinylated secondary, SABC and DAB).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported in the supplied evidence; the selected A01392 paraffin-section caption does not report a fixative (caption: fixative not stated). Heat retrieval with citrate buffer at pH 6 for 20 minutes was used for the pictured renal cancer section, but its necessity in epididymis is unreported (caption: renal cancer IHC retrieval). No supplied comparison establishes whether frozen sections or IF/ICC are easier, and no epididymis-specific artefact is reported; assess background with the controls above.
HPA tissue IHC evidence for ALDH1A1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium 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 |
|---|---|---|---|---|
| Epididymis | Glandular cells | High | Protein (IHC) | HPA → |
| Stomach | Glandular cells | High | Protein (IHC) | HPA → |
| Adipose tissue | Adipocytes | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Cerebral cortex | Endothelial cells | Not detected | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Colon | Endothelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced ALDH1A1 IHC Tips
Troubleshoot ALDH1A1 staining in paraffin sections by checking retrieval, cytoplasmic localisation, detection background, and cell-specific scoring (datasheet A01392; HPA tissue IHC).
How should I optimise retrieval when ALDH1A1 staining is weak?
Start with heat-mediated retrieval in citrate buffer at pH 6 for 20 minutes (datasheet A01392). Check deparaffinisation and compare sections containing expected positive cells before altering retrieval; epididymal glandular cells show high staining, while hepatocytes show medium staining (standard IHC practice; HPA tissue IHC). Keep cooling and detection conditions matched: the selected paraffin-section image used 1 μg/ml primary antibody overnight at 4°C (datasheet A01392). If staining remains weak, compare a longer citrate treatment or another buffer as a fallback, assessing tissue preservation and cytoplasmic specificity alongside signal strength (standard IHC practice; HPA tissue IHC).
Could fixation explain variable ALDH1A1 staining between paraffin sections?
The selected A01392 image documents a paraffin section but does not identify its fixative, so ALDH1A1-specific fixation sensitivity is unknown (datasheet A01392). Record the fixative, fixation duration, processing history, and section age for each sample, then compare matched controls processed alongside the study tissue (standard IHC practice). If staining differs, change one processing variable at a time while holding citrate retrieval at pH 6 and the primary antibody at the documented 1 μg/ml starting point (datasheet A01392; standard IHC practice). Judge each change by preserved morphology and expected cytoplasmic staining in appropriate cells, rather than staining intensity alone (HPA tissue IHC; standard IHC practice).
Should ALDH1A1 signal be nuclear, membranous, or cytoplasmic?
Score cytoplasmic staining as the expected pattern: ALDH1A1 is annotated in the cytoplasm and cytosol, and tissue IHC shows cytoplasmic expression in selected tissues (UniProt P00352 subcellular; HPA tissue IHC). HPA also reports enhanced cytosolic localisation in cell imaging, while UniProt lists no transmembrane segment (HPA subcellular; UniProt P00352 topology). Examine morphology and counterstain on the same section to distinguish cytoplasm from adjacent nuclei or cell borders (standard IHC practice). Predominantly crisp nuclear or circumferential membrane staining should prompt review of detection background, antibody concentration, and positive controls before it is assigned to ALDH1A1 (UniProt P00352 subcellular; standard IHC practice).
How can I investigate staining that seems epitope dependent?
The supplied record lists 0 ALDH1A1 isoforms and no annotated domains, so an isoform-specific staining explanation is unsupported here (UniProt P00352 isoforms and domains). ALDH1A1 has annotated modified residues, including acetyllysines and phosphothreonine, but their effect on this antibody’s tissue epitope is unspecified (UniProt P00352 modified residues; datasheet A01392). Confirm the antibody’s stated immunogen or epitope, if available, before proposing epitope masking as a target-specific mechanism (standard IHC practice). Compare matched sections using the documented citrate pH 6 retrieval, then assess whether any retrieval change improves expected cytoplasmic staining without increasing staining in negative cells (datasheet A01392; HPA tissue IHC; standard IHC practice).
How should I check ALDH1A1 in a multiplex IF follow-up?
Use a marker for the expected cell type in a separate channel, then verify that ALDH1A1 signal occupies its cytoplasm rather than merely overlapping the cell outline (HPA tissue IHC; HPA subcellular). For example, hepatocytes show medium ALDH1A1 staining in tissue IHC; choose a hepatocyte marker only after confirming its suitability for the specimen (HPA tissue IHC; standard IF practice). Select fluorophores after checking unstained tissue for autofluorescence, and include single-stain controls when assessing channel bleed-through (standard IF practice). Because ALDH1A1 is cytosolic and lacks a transmembrane segment, use a permeabilisation condition that permits antibody access to the cell interior, then check that morphology remains intact (UniProt P00352 subcellular and topology; standard IF practice).
What causes diffuse brown staining in ALDH1A1 IHC?
Check whether diffuse DAB colour persists in a section processed without primary antibody; that pattern directs attention to the detection system or endogenous tissue activity (standard IHC practice). The documented A01392 image used a biotinylated secondary antibody, a streptavidin-biotin complex, and DAB, so include an appropriate detection-only control when assessing this workflow (datasheet A01392; standard IHC practice). A peroxidase block and, where indicated, an endogenous-biotin control address two possible sources of chromogenic background (standard IHC practice). Compare any residual staining with expected cytoplasmic signal in selected cells, and adjust blocking, washes, or detection exposure while retaining a positive control (HPA tissue IHC; standard IHC practice).
How should I quantify ALDH1A1 staining across heterogeneous tissue? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and tissue region before scoring, then record the percentage of cells with cytoplasmic ALDH1A1 staining and their intensity (HPA tissue IHC; standard IHC practice). An H-score can combine percentages at intensity grades 0–3 into a 0–300 result; keep thresholds, illumination, and batch controls consistent (standard IHC practice). Normalise the positive-cell count or stained area to the number of evaluable cells or evaluable tissue area in the same region, and exclude folds and necrosis (standard IHC practice). Report cell types separately where composition varies, since HPA shows high glandular-cell staining in epididymis but medium hepatocyte staining in liver (HPA tissue IHC; standard IHC practice).
When is ALDH1A1 staining convincing rather than artefactual?
A convincing result has cell-associated cytoplasmic staining in an appropriate population, consistent with ALDH1A1’s cytosolic annotation and selected-tissue IHC pattern (UniProt P00352 subcellular; HPA tissue IHC). Compare expected positive cells, such as epididymal glandular cells, with a relevant low or undetected population processed in the same run (HPA tissue IHC; standard IHC practice). Treat staining confined to section edges, folds, necrotic areas, or an unexpected nuclear or membrane compartment as a reason to review the slide and controls (UniProt P00352 subcellular; standard IHC practice). If colour remains without primary antibody, investigate endogenous peroxidase activity and the biotin-based detection workflow before interpreting it as ALDH1A1 (datasheet A01392; standard IHC practice).
Boster reagents
Best ALDH1A1 / Aldehyde dehydrogenase 1A1 IHC Antibodies
The catalog shows ALDH1A1 IHC images from human and mouse tissues and IF/ICC images from A431 and A549 cells (catalog IHC and IF image captions).
Real IHC data
Anti-Retinal dehydrogenase 1 ALDH1A1 Antibody ®
Cat # A01392
Real IHC data
Anti-ALDH1A1 Antibody ® (monoclonal, 4C3)
Cat # M01392-2
Real IHC data
Anti-Retinal dehydrogenase 1 ALDH1A1 Antibody ®
Cat # PA1671
Real IHC data
Anti-ALDH1A1 Rabbit Monoclonal Antibody
Cat # M01392-3
Real IHC data
Anti-ALDH1A1 Rabbit Monoclonal Antibody
Cat # M01392-1
A01392 shows IHC in paraffin sections of human renal cancer and IF/ICC in A431 and A549 cells (A01392 image captions); M01392-2 shows IHC in paraffin sections of human gall bladder adenosquamous carcinoma and IF/ICC in A549 cells (M01392-2 image captions); PA1671 shows IHC in paraffin sections of human lung cancer and IF/ICC in A549 cells (PA1671 image captions). M01392-3 shows IHC in mouse, rat, and human lung (M01392-3 IHC captions), while M01392-1 shows IHC in a paraffin section of human liver cancer (M01392-1 IHC caption).
Which to pick: For paraffin-section tissue IHC, A01392 has human renal cancer and mouse stomach images, with citrate retrieval at pH 6 for 20 minutes and primary antibody at 1 μg/mL overnight at 4°C (A01392 IHC captions); its fixative is unreported (A01392 IHC captions). For human IF/ICC, A01392 has A431 and A549 images at 2 μg/mL (A01392 IF captions), while M01392-2 offers mouse monoclonal clone 4C3 with an A549 image at 5 μg/mL (catalog clone; M01392-2 IF caption). For cross-species tissue IHC, M01392-3 has mouse, rat, and human lung images and a listed 1:500–1:2000 IHC range; its image captions do not report the fixative or retrieval conditions (M01392-3 IHC captions; catalog IHC dilution).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P00352 (AL1A1_HUMAN, Aldehyde dehydrogenase 1A1).
- Human Protein Atlas. ALDH1A1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. ALDH1A1 subcellular location (ICC-IF): Localized to the cytosol..
- Human Protein Atlas. ALDH1A1 antibody validation summary (2 antibodies).
- A neutrophil-biomimic platform for eradicating metastatic breast cancer stem-like cells by redox microenvironment modulation and hypoxia-triggered differentiation therapy. Acta pharmaceutica Sinica. B 2023 — PMC9939302.
- Low expression of aldehyde dehydrogenase 1A1 (ALDH1A1) is a prognostic marker for poor survival in pancreatic cancer. BMC cancer 2011 — PMC3135572.
- ALDH1A1 expression is associated with poor differentiation, 'right-sidedness' and poor survival in human colorectal cancer. PloS one 2018 — PMC6181398.
- Colorectal adenoma stem-like cell populations: associations with adenoma characteristics and metachronous colorectal neoplasia. Cancer prevention research (Philadelphia, Pa.) 2013 — PMC4079278.
- PubMed PMID:2591967 — UniProt-cited evidence.
- PubMed PMID:8214422 — UniProt-cited evidence.
- PubMed PMID:19296407 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ALDH1A1 (Aldehyde dehydrogenase 1A1). Expected localisation Cytoplasmic staining in selected tissues (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A01392). Validated IHC antibody: A01392 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Epididymis (Glandular cells); negative Adrenal gland. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human renal cancer tissues; fixative not specified (datasheet A01392); 2. Fixation: Image fixative and duration unreported (datasheet A01392); 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: Citrate pH 6 , 20 min (datasheet A01392); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01392); 8. Primary antibody: Rabbit anti-ALDH1A1, 0.5-1μg/ml (datasheet A01392); 9. Primary incubation: Overnight at 4 °C (datasheet A01392). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Antibody staining and RNA show medium consistency (HPA tissue IHC); Isoform / epitope: 0 annotated isoforms; mature chain spans 2–501 (UniProt); Regulation: Regulation is not specified (UniProt). Evidence: UniProt P00352, HPA tissue IHC · Enhanced, HPA ICC-IF · cytosol., Datasheet A01392, PMC3135572, PMC6181398. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ALDH1A1/immunohistochemistry-ihc-guide.