ALDH3A2 / Aldehyde dehydrogenase family 3 member A2 · IHC design guide

Design Immunohistochemistry for ALDH3A2

Plan ALDH3A2 staining in paraffin sections using the observed cytoplasmic tissue pattern and the catalog antibody's IHC conditions (HPA tissue IHC; datasheet PB9982). Choose cell-specific controls and account for variation in glandular staining across tissues (HPA tissue IHC).

Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use

Immunohistochemistry protocol sheet for ALDH3A2 (IHC for ALDH3A2): expected localisation Cytoplasmic tissue staining; ER and microsome membrane protein (HPA tissue IHC; UniProt), antibody PB9982, validated IHC image, and IHC protocol steps — Printable **ALDH3A2** IHC protocol sheet — expected localisation Cytoplasmic tissue staining; ER and microsome membrane protein (HPA tissue IHC; UniProt), antibody PB9982, controls and protocol steps. Open the full ALDH3A2 IHC guide →

Navigate to: Protocols Staining pattern Controls Antibodies

ALDH3A2 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; ER and microsome membrane protein (HPA tissue IHC; UniProt)
	Staining pattern	Cytoplasmic staining in glandular, epithelial and neuronal cells (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet PB9982)
	Positive control ⓘ	Adrenal gland+4 more · see all
	Negative control ⓘ	Appendix+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	Glandular staining varies by tissue (HPA tissue IHC)
	Regulation	Liver-enhanced RNA expression (HPA tissue RNA)
	Isoform / epitope	2 isoforms; map the epitope to the cytoplasmic region (UniProt)

Section 1

Recommended ALDH3A2 IHC & IF Protocols

The catalog antibody protocol uses EDTA pH 8.0 retrieval (datasheet PB9982). The published protocols below cover ovarian, esophageal, and breast tissues (PMC3458927; PMC7935981; PMC12715930).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet PB9982)
Fixation	Image fixative and duration unreported (datasheet PB9982); 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 PB9982); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet PB9982)
Primary antibody	Rabbit anti-ALDH3A2, 0.5-1μg/ml (datasheet PB9982)
Primary incubation	Overnight at 4 °C (datasheet PB9982)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet PB9982)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	ALDH3A2-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several tissues. No signal in the no-primary control.

💡Decision noteStart with EDTA pH 8.0 for the catalog antibody (datasheet PB9982); the published esophageal protocol used EDTA pH 9.0 for ALDH3A2 (PMC7935981).

Section 2

What Is the Expected ALDH3A2 Staining Pattern?

ALDH3A2 is an endoplasmic reticulum and microsome membrane protein with a cytoplasmic region spanning residues 1–463 and one transmembrane segment at 464–484 (UniProt P51648 topology). In paraffin section IHC, expect cytoplasmic staining in selected glandular and epithelial cells; adrenal glandular and bronchial respiratory epithelial cells are reported as High (HPA tissue IHC). HPA rates the tissue profile Enhanced, with medium consistency between staining and RNA expression (HPA tissue IHC).

What am I looking at on my slide?
Distinct cytoplasmic staining in adrenal glandular or bronchial respiratory epithelial cells.	These are the supplied High IHC examples (HPA tissue IHC). Cytoplasmic staining is consistent with the reported tissue profile and with an ER or microsome membrane protein whose large region faces the cytoplasm (HPA tissue IHC; UniProt P51648 topology). Chromogenic IHC alone does not resolve the ER.
Cytoplasmic staining in colon, duodenum or endometrial glandular cells, or in the listed neuronal cells.	A Medium result can fit the HPA observations: glandular cells in those three tissues, and neuronal cells in caudate or cerebral cortex and Purkinje cells in cerebellum (HPA tissue IHC). Judge the identified cell population rather than treating every cell in a section as a positive control.
Predominantly nuclear, sharply surface restricted, or extracellular deposits.	These do not match HPA's cytoplasmic tissue profile or its approved ER and cytosol ICC-IF locations (HPA tissue IHC; HPA subcellular). Check morphology and detection controls before calling them ALDH3A2; misplaced signal can reflect staining artefact (general IHC practice).
Strong signal in cells listed as Not detected, such as appendix glandular cells or bone marrow hematopoietic cells.	That conflicts with the supplied cell specific IHC observations (HPA tissue IHC). Cross-reactivity or endogenous detection activity is possible, but the image alone cannot identify the cause (general IHC practice). Confirm the cell identity and compare a detection control before assigning target expression.
Diffuse color across cells and tissue spaces, or no staining in a known positive section.	Neither gives a readable cell specific pattern (general IHC practice). Diffuse color warrants background and detection controls; a blank adrenal or bronchus section warrants checking section quality and the IHC run before interpreting a sample as negative (HPA tissue IHC; general IHC practice).

💡Expected ALDH3A2 appearanceCall a positive result when cytoplasmic staining is distinct in adrenal glandular or bronchial respiratory epithelial cells, where HPA reports High staining; dominant nuclear or diffuse extracellular color is suspect (HPA tissue IHC; general IHC practice).

How each factor affects the staining
Cell and tissue choice	Adrenal glandular and bronchial respiratory epithelial cells provide High reference patterns; colon, duodenum and endometrial glandular cells are Medium (HPA tissue IHC). Appendix glandular and bone marrow hematopoietic cells are listed as Not detected; use the specified cell type when comparing sections (HPA tissue IHC).
Antibody validation	HPA lists HPA014769 as IHC Enhanced and CAB020692 as IHC Approved (HPA antibodies). These labels describe antibody validation; the tissue profile separately has Enhanced reliability and medium staining to RNA consistency (HPA tissue IHC). Compare patterns with that distinction in mind.
Topology and epitope interpretation	Residues 1–463 are cytoplasmic and 464–484 form the transmembrane segment (UniProt P51648 topology). No antibody epitope is supplied, so topology cannot establish epitope exposure or an ALDH3A2 specific antigen retrieval requirement.
Isoforms and liver evidence	UniProt lists 2 isoforms and reports protein detection in liver (UniProt P51648). HPA reports liver enhanced RNA specificity (HPA tissue IHC). Neither item supplies an isoform specific IHC pattern or a liver IHC intensity in this payload; do not assign either.
IF/ICC: What localization is expected?	HPA approves endoplasmic reticulum and cytosol localization in ICC-IF and lists images from OE19 and SiHa (HPA subcellular). This is a localization comparison only; it does not turn an IF/ICC method into an IHC-P protocol.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Adrenal glandular or bronchial respiratory epithelial cells show no clear signal.	A blank expected positive may reflect a failed IHC run or unsuitable section; it does not by itself establish absence of ALDH3A2 (HPA tissue IHC; general IHC practice).	Review tissue morphology, run controls and the catalog antibody's IHC-P instructions. Check the prescribed retrieval, primary antibody dilution and detection steps as general IHC practice; no ALDH3A2 specific retrieval effect is supplied.
Color is widespread with little cell definition.	Background from nonspecific binding or the detection system can obscure the cytoplasmic pattern (general IHC practice).	Compare an omission control, inspect blocking and washes, and review primary antibody concentration and detection exposure (general IHC practice). Reassess only cells whose boundaries remain interpretable.
Signal is strong in an HPA Not detected cell population.	Cross-reactivity or endogenous detection activity is possible; HPA's Not detected label is an observation for that named cell population, not proof that the whole organ must be blank (HPA tissue IHC; general IHC practice).	Verify cell identity and compare omission and detection controls. If chromogenic enzyme detection is used, assess its endogenous activity control as appropriate (general IHC practice).
Most color appears nuclear or extracellular.	The dominant compartment disagrees with HPA's cytoplasmic tissue profile and approved ER and cytosol ICC-IF locations (HPA tissue IHC; HPA subcellular).	Inspect morphology and background controls, then compare a section containing an HPA High cell population. Do not score compartment mismatches as a confirmed ALDH3A2 positive (general IHC practice).
A liver section stains, but its intensity seems inconsistent with other tissues.	UniProt reports liver protein and HPA reports liver enhanced RNA specificity, but the supplied HPA IHC payload gives no liver staining level (UniProt P51648; HPA tissue IHC).	Record the observed liver cell type, compartment and intensity without assigning an expected IHC grade. Use the listed High IHC cell populations for an intensity comparison (HPA tissue IHC).
Two antibodies give different staining patterns.	HPA records different IHC validation statuses for HPA014769 and CAB020692; status alone does not explain a particular disagreement (HPA antibodies).	Compare the same named cell populations, compartment and run controls under each antibody's validated IHC conditions (HPA tissue IHC; general IHC practice). Treat discordant staining as unresolved until the pattern is supported.

Source: UniProt P51648 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing ALDH3A2 staining

IHC analysis of ALDH3A2 using anti-ALDH3A2 antibody (PB9982). ALDH3A2 was detected in a paraffin-embedded section of human liver cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1 μg/ml rabbit anti-ALDH3A2 Antibody (PB9982) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

PB9982 · IHCIHC analysis of ALDH3A2 using anti-ALDH3A2 antibody (PB9982). ALDH3A2 was detected in a paraffin-embedded section of human liver cancer tiss

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000072210-ALDH3A2/tissue/cerebral+cortex#imid_4401120

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000072210-ALDH3A2/tissue/colon#imid_4401062

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000072210-ALDH3A2/tissue/liver#imid_4401063

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000072210-ALDH3A2/tissue/kidney#imid_4401056

HPA · ICC-IF OE19Human Protein Atlas immunofluorescence, OE19, antibody HPA014769; green = ALDH3A2, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

Real IHC / IF data behind the staining-pattern expectations in this section.

Sample controls for ALDH3A2 IHC & IF

🧪Run bronchus first: respiratory epithelial cells should stain (HPA: High in bronchus respiratory epithelial cells); use appendix glandular cells as the negative tissue (HPA: Not detected in appendix glandular cells). On the bronchus slide, adjacent cells without visible staining should resemble the no-primary background, but the supplied HPA rows do not establish that those cells are ALDH3A2-negative.

Positive control tissue: Adrenal gland (Glandular cells, HPA High)

Negative control tissue: Appendix (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ALDH3A2 in OE19, SiHa, with annotated localisation: Endoplasmic reticulum (approved), Cytosol (approved) (HPA subcellular).

Technical controls: Include no-primary (secondary-only) and matched rabbit IgG isotype controls (selected caption: rabbit primary antibody), plus ALDH3A2 knockout tissue or a validated immunizing-peptide block as a biological specificity control (standard IHC practice). Quench endogenous peroxidase and check for endogenous biotin when using the caption’s biotin-based DAB detection (selected caption: biotinylated secondary, SABC and DAB).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence; the selected PB9982 paraffin-section caption does not state a fixative (selected caption: fixative unreported). The documented IHC example uses heat-mediated retrieval in EDTA at pH 8.0, but does not establish whether retrieval is required (selected caption: EDTA retrieval). No supplied comparison establishes that frozen sections or IF are easier; in bronchus, interpret epithelial DAB staining against the negative controls and any visible airway pigment or mucus (standard IHC practice).

HPA tissue IHC evidence for ALDH3A2

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
Adrenal gland	Glandular cells	High	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	High	Protein (IHC)	HPA →
Caudate	Neuronal cells	Medium	Protein (IHC)	HPA →
Cerebellum	Purkinje cells	Medium	Protein (IHC)	HPA →
Cerebral cortex	Neuronal cells	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Breast	Adipocytes	Not detected	Protein (IHC)	HPA →
Cervix	Glandular cells	Not detected	Protein (IHC)	HPA →
Fallopian tube	Glandular cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced ALDH3A2 IHC Tips

Troubleshoot ALDH3A2 staining in paraffin sections by checking retrieval, cellular distribution, controls and scoring before interpreting chromogenic signal.

What retrieval should I try first if ALDH3A2 staining is weak?

Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet PB9982). The selected tissue image used this buffer before overnight incubation at 4°C with 1 μg/ml antibody, so compare retrieval changes against that documented staining workflow (datasheet PB9982). If staining remains weak, test retrieval time on adjacent sections while keeping antibody concentration, detection and DAB development constant (standard IHC practice). Excess retrieval can damage morphology or increase nonspecific signal; judge any gain against preserved tissue structure and a matched negative control (standard IHC practice).

Could fixation explain weak or uneven ALDH3A2 staining?

Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative (datasheet PB9982). Record the actual fixative and fixation duration for each specimen, then compare similarly processed sections before attributing staining differences to ALDH3A2 abundance (standard IHC practice). If signal is uneven, inspect whether tissue edges stain more strongly than the center and review section thickness, processing history and retrieval consistency (standard IHC practice). Use the documented EDTA pH 8.0 retrieval as a common starting condition; do not treat its success in one paraffin section as evidence that any fixation condition preserves the epitope (datasheet PB9982).

Where should convincing ALDH3A2 chromogenic staining appear?

Expect predominantly cytoplasmic staining in tissue sections, consistent with the reported tissue profile (HPA: cytoplasmic expression in several tissues). ALDH3A2 associates with endoplasmic reticulum and microsome membranes, with residues 1–463 facing the cytoplasm and a transmembrane segment at 464–484 (UniProt P51648 topology). Light-microscopy DAB signal may not resolve those membranes, so score a credible cytoplasmic pattern without requiring a visible reticular outline (standard IHC practice). Treat isolated nuclear or extracellular staining cautiously, particularly if it lacks the expected cell distribution or persists in a matched negative control (UniProt P51648 topology; standard IHC practice).

Can epitope position change how I interpret an ALDH3A2-negative section?

ALDH3A2 has 2 annotated isoforms, but the supplied antibody evidence does not identify its recognized epitope or establish isoform specificity (UniProt P51648 isoforms; datasheet PB9982). Its cytoplasmic region spans residues 1–463, followed by a membrane-spanning segment at 464–484; phosphorylation at serine 293 is annotated (UniProt P51648 topology and modified residues). These features locate possible epitope contexts but do not establish that splicing or phosphorylation changes this antibody’s tissue staining (UniProt P51648 record; datasheet PB9982). If an expected cell population is negative, verify section quality and retrieval, then seek epitope mapping or independent antibody evidence before claiming isoform loss (standard IHC practice).

How should I check an ALDH3A2 pattern by multiplex IF?

For a separate IF experiment, pair ALDH3A2 with a validated marker for the cell population being examined, such as respiratory epithelial cells in bronchus (HPA: high in bronchial respiratory epithelial cells). Choose spectrally separated fluorophores and inspect an unstained section in each channel before assigning tissue autofluorescence to ALDH3A2 (standard IF practice). Because residues 1–463 face the cytoplasm, include controlled permeabilisation when testing accessibility of an epitope within that region; the antibody’s epitope position is unreported (UniProt P51648 topology; datasheet PB9982). Compare single-stain and secondary-only controls, and assess whether the ALDH3A2 signal follows the expected cytoplasmic distribution (HPA: cytoplasmic tissue expression; standard IF practice).

What should I check when DAB staining is diffuse or widespread?

The selected paraffin-section workflow used 10% goat serum, a biotinylated secondary antibody, a streptavidin–biotin complex and DAB (datasheet PB9982). When staining is diffuse, compare primary-omission and secondary-only controls, and verify that the blocking reagent matches the detection system (standard IHC practice). Check endogenous peroxidase blocking and, for this biotin-based method, assess endogenous biotin as separate sources of chromogenic signal (datasheet PB9982; standard IHC practice). If controls are clean, review primary concentration against the documented 1 μg/ml, wash stringency and DAB development time, changing one variable at a time (datasheet PB9982; standard IHC practice).

How should I quantify ALDH3A2 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and analysis area before scoring, then score cytoplasmic DAB signal within those cells (HPA: cytoplasmic tissue expression; standard IHC practice). An H-score combines the percentage of cells at intensity grades 0–3 into a 0–300 value; also report percentage positive if intensity thresholds are reproducible (standard IHC practice). For heterogeneous tissue, record positive-cell density per mm² and normalize counts to the sampled, viable tissue area or the number of cells in the defined population (standard IHC practice). Apply the same threshold, counterstain review and imaging settings across sections, and report excluded necrotic or damaged regions (standard IHC practice).

How can I distinguish real ALDH3A2 signal from tissue artefact?

A plausible positive is cytoplasmic signal in an intact cell population, consistent with ALDH3A2’s reported tissue pattern and ER-associated topology (HPA: cytoplasmic tissue expression; UniProt P51648 topology). Compare the pattern with documented high staining in adrenal glandular cells or bronchial respiratory epithelial cells, while treating tissue profiles as context rather than proof of antibody specificity (HPA: high in both populations). Nuclear-only deposits, staining confined to section edges or necrotic areas, and signal in a primary-omission control warrant investigation (UniProt P51648 topology; standard IHC practice). Check endogenous peroxidase and biotin contributions before interpreting DAB signal from the documented biotin-based detection workflow (datasheet PB9982; standard IHC practice).

Boster reagents

Best ALDH3A2 / Aldehyde dehydrogenase family 3 member A2 IHC Antibodies

PB9982 has real IHC data from a human liver cancer paraffin section (PB9982 image caption); the catalog lists human and rat reactivity, with no IF data (PB9982 catalog).

Real IHC data

Anti-ALDH3A2 Antibody ®

Cat # PB9982

View product →

PB9982 is the sole rendered SKU and is listed for IHC and WB with human and rat reactivity (PB9982 catalog). Its IHC image shows staining in a human liver cancer paraffin section (PB9982 image caption).

Which to pick: Choose PB9982 for human tissue IHC in paraffin sections (PB9982 image caption); the fixative is unreported (PB9982 image caption). No listed SKU has IF/ICC validation or an IF image (PB9982 catalog). PB9982 lists rat reactivity, but the supplied IHC image documents human tissue only (PB9982 catalog; PB9982 image caption).

Each figure is that product's own IHC / IF validation image from its datasheet.

References

UniProt Consortium. UniProt entry P51648 (AL3A2_HUMAN, Aldehyde dehydrogenase family 3 member A2).
Human Protein Atlas. ALDH3A2 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. ALDH3A2 subcellular location (ICC-IF): Localized to the endoplasmic reticulum and cytosol..
Human Protein Atlas. ALDH3A2 antibody validation summary (2 antibodies).
Characterization of aldehyde dehydrogenase isozymes in ovarian cancer tissues and sphere cultures. BMC cancer 2012 — PMC3458927.
Endogenous aldehyde accumulation generates genotoxicity and exhaled biomarkers in esophageal adenocarcinoma. Nature communications 2021 — PMC7935981.
miR-1182-mediated ALDH3A2 inhibition affects lipid metabolism and progression in ccRCC by activating the PI3K-AKT pathway. Translational oncology 2024 — PMC10730858.
ALDH3A2 targets arachidonic acid to promote cell metastasis in TNBC via AMPK/m-TOR signaling pathway. Breast cancer research : BCR 2025 — PMC12715930.
PubMed PMID:8528251 — UniProt-cited evidence.
PubMed PMID:9027499 — UniProt-cited evidence.
PubMed PMID:9070922 — UniProt-cited evidence.