Metabolism and Oxidative Stress Detoxification, and Its Detection Applications

Aldehyde dehydrogenase (ALDH) is a class of oxidoreductases that use NAD+ or NADP+ as cofactors and mainly catalyze the oxidation of aldehyde substrates into corresponding carboxylic acids. Aldehydes can originate from ethanol metabolism, lipid peroxidation, sugar oxidation, drug metabolism, and exposure to environmental toxicants. Reactive aldehydes such as acetaldehyde, 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) can readily modify proteins, nucleic acids, and membrane lipids. By reducing aldehyde reactivity, ALDH plays an important role in aldehyde detoxification, oxidative stress buffering, and maintenance of cellular homeostasis.

Keywords: aldehyde dehydrogenase; ALDH; aldehyde metabolism; acetaldehyde; 4-HNE; MDA; oxidative stress; detoxification metabolism; enzyme activity assay

1 Basic Concepts of ALDH

1.1 Enzymatic Function

The core function of ALDH is to oxidize aldehyde substrates into carboxylic acids. During the reaction, the aldehyde group is oxidized, while NAD⁺ or NADP⁺ is reduced to NADH or NADPH. Compared with aldehydes, the corresponding carboxylic acids usually have lower reactivity and weaker ability to modify proteins, DNA, and membrane lipids. Therefore, ALDH-catalyzed reactions have clear detoxification significance.

1.2 Family Members

Mammalian ALDH is a multi-member enzyme family. Different isoforms have different tissue distributions, subcellular localizations, and substrate preferences. ALDH2 is mainly localized in mitochondria and is a key enzyme in acetaldehyde clearance and lipid peroxidation aldehyde detoxification. It is suitable for studies of ethanol metabolism, mitochondrial aldehyde toxicity, and myocardial/hepatic oxidative injury. The ALDH1A family participates in the oxidation of retinaldehyde to retinoic acid and is related to cell differentiation, embryonic development, stem cell properties, and cancer stem-like cell research. ALDH3A1 is often studied in the cornea, epithelial tissues, and drug metabolism. ALDH5A1 is associated with gamma-aminobutyric acid metabolism. Total ALDH activity is suitable for evaluating overall aldehyde oxidation capacity, but it cannot directly represent the function of a specific isoform.

1.3 Biological Positioning

ALDH is widely distributed in the liver, gastrointestinal tract, myocardium, brain, kidney, lung, cornea, hematopoietic system, and other tissues. The liver is an important organ for ethanol metabolism and aldehyde detoxification. Myocardial and neural tissues are sensitive to lipid peroxidation-derived aldehydes. Mitochondrial ALDH2 is important for maintaining energy metabolism and reducing aldehyde-modification damage.

2 Role of ALDH in Aldehyde Metabolism

2.1 Ethanol Metabolism and Acetaldehyde Clearance

(1) Ethanol oxidation chain

After ethanol enters the body, it is first converted to acetaldehyde by enzymes such as alcohol dehydrogenase or CYP2E1. Acetaldehyde can form adducts with proteins and DNA, triggering inflammation, oxidative stress, and cellular functional damage. ALDH further oxidizes acetaldehyde to acetate, which is a key step in reducing acetaldehyde toxicity.

(2) Key role of ALDH2

ALDH2 is the core mitochondrial enzyme for acetaldehyde clearance. When ALDH2 activity is insufficient, acetaldehyde can accumulate easily, leading to flushing, increased heart rate, headache, nausea, and other reactions after alcohol intake. Long-term acetaldehyde exposure also increases oxidative stress burden in the liver, gastrointestinal tract, and cardiovascular system.

(3) Detection significance

In ethanol metabolism research, ALDH activity is suitable for combined analysis with ADH activity, acetaldehyde content, acetate production, NADH/NAD+ ratio, and oxidative stress indicators. When ADH activity increases while ALDH activity is insufficient, the risk of acetaldehyde accumulation rises.

2.2 Metabolism of Lipid Peroxidation-Derived Aldehydes

(1) 4-HNE clearance

4-HNE is an important reactive aldehyde formed after peroxidation of polyunsaturated fatty acids. It can undergo addition reactions with cysteine, histidine, and lysine residues, thereby altering protein structure and signaling function. ALDH can oxidize part of 4-HNE into corresponding carboxylic acids, reducing its electrophilic toxicity.

(2) MDA-related metabolism

MDA is a commonly used indicator of lipid peroxidation and can also form adducts with proteins and nucleic acids. Increased MDA levels usually reflect enhanced membrane lipid oxidation. If ALDH activity decreases at the same time, this suggests that the balance between generation and clearance of lipid peroxidation products may be disrupted.

(3) Membrane lipid protection

Cell membranes, mitochondrial membranes, and endoplasmic reticulum membranes are rich in unsaturated fatty acids and can easily generate reactive aldehydes after oxidation. ALDH works together with systems such as GSH-Px and glutathione transferase to process lipid peroxidation products, helping maintain membrane structure and membrane protein function.

2.3 Retinaldehyde and Developmental Regulation

ALDH1A1, ALDH1A2, and ALDH1A3 can catalyze the oxidation of retinaldehyde to retinoic acid. Retinoic acid participates in embryonic development, cell differentiation, epithelial homeostasis, and immune regulation. Therefore, some ALDH isoforms are not only detoxification enzymes but also have regulatory functions in signaling metabolism.

In stem cell and tumor research, high ALDH activity is often used to identify specific cell subpopulations. Its significance should be interpreted according to tissue source, isoform expression, and functional experiments, and should not be simply equated with universal elevation of all ALDH isoforms.

3 ALDH and Oxidative Stress Detoxification

3.1 Aldehydes as Amplifiers of Oxidative Stress

ROS can directly oxidize proteins, lipids, and nucleic acids, and can also generate secondary toxic products such as 4-HNE, MDA, and acrolein through lipid peroxidation. These reactive aldehydes have relatively long lifetimes and broad diffusion ranges, allowing them to continuously modify intracellular proteins and membrane structures. By reducing free aldehyde levels, ALDH limits the expansion of oxidative stress from primary ROS damage to aldehyde toxicity.

3.2 Limiting Protein Modification by ALDH

Reactive aldehydes can form adducts with enzymes, receptors, transporters, and cytoskeletal proteins, resulting in reduced enzyme activity, protein misfolding, or abnormal signaling. When ALDH activity is maintained at normal levels, aldehyde-protein adduct formation can be reduced. In mitochondria, ALDH2 has protective significance for respiratory chain complexes, membrane potential, and ATP production.

3.3 Synergy with the Glutathione System

Aldehyde detoxification does not rely entirely on ALDH. GSH-Px can reduce lipid peroxide formation, glutathione transferase can promote conjugation of reactive aldehydes with GSH, and ALDH further oxidizes free aldehydes or some aldehyde metabolites. If GSH is depleted, the GSH/GSSG ratio decreases, or GSH-Px activity is insufficient, the lipid peroxidation-derived aldehyde burden increases and ALDH workload also rises.

4 Biological Significance of Changes in ALDH Activity

4.1 Decreased ALDH Activity

Decreased ALDH activity indicates weakened aldehyde clearance capacity. If 4-HNE, MDA, protein carbonyls, or ROS also increase, aldehyde toxicity and oxidative damage may accumulate simultaneously. This is commonly seen in alcohol exposure, mitochondrial dysfunction, ischemia-reperfusion, chronic inflammation, and toxic injury models.

4.2 Increased ALDH Activity

Increased ALDH activity may represent enhanced compensatory detoxification or enrichment of ALDH-high cell subpopulations. If increased activity is accompanied by reduced aldehyde burden and lower injury indicators, it tends to indicate protective compensation. If it is accompanied by enhanced drug resistance, proliferation, or stemness markers, further detection of isoforms such as ALDH1A1 and ALDH1A3 is needed.

4.3 ALDH2-Specific Changes

ALDH2 is closely related to acetaldehyde clearance, mitochondrial aldehyde detoxification, and cardiovascular protection. When ALDH2 activity is insufficient, acetaldehyde and lipid peroxidation-derived aldehydes are more likely to accumulate, increasing the risk of mitochondrial protein modification, decreased membrane potential, and energy metabolism impairment. In studies of alcohol-related liver injury, myocardial ischemia-reperfusion, neural injury, and metabolic diseases, ALDH2 is a key detection target.

5 ALDH Detection Methods

5.1 Enzyme Activity Detection

ALDH activity detection is often based on the reduction of NAD+ or NADP+ to NADH or NADPH, and evaluates aldehyde substrate oxidation capacity through changes in absorbance or fluorescence signals. This method is suitable for detecting cell lysates, tissue homogenates, purified enzymes, and subcellular fractions. The substrate type, cofactor type, pH, temperature, and sample normalization method should be clearly defined.

Different substrates correspond to different ALDH isoform preferences. Acetaldehyde is more suitable for ethanol metabolism research, 4-HNE is more suitable for lipid peroxidation aldehyde detoxification studies, and retinaldehyde is more suitable for ALDH1A family and retinoic acid pathway research.

5.2 ALDH Protein Level Detection

ELISA, Western blot, immunohistochemistry, and immunofluorescence can be used to detect ALDH protein expression. Protein level detection is suitable for observing changes in ALDH1A1, ALDH2, ALDH3A1, and other isoforms. However, protein expression level is not necessarily equal to enzyme activity; oxidative modification, cofactor supply, and subcellular environment can all affect actual catalytic capacity.

5.3 Flow Cytometric Detection of Cellular ALDH Activity

Some cell studies use cell-permeable fluorescent substrates that enter cells, are converted by ALDH, and are retained intracellularly, allowing ALDH-high cell populations to be identified by flow cytometry. This method is commonly used for stem cells, cancer stem-like cells, and drug-resistant cell subpopulation analysis. ALDH inhibitor controls should be included to distinguish true enzyme activity signals from nonspecific background.

5.4 Detection of Aldehyde Metabolites

ALDH function can also be indirectly evaluated by changes in substrates and products. Ethanol metabolism experiments can detect acetaldehyde and acetate; lipid peroxidation studies can detect 4-HNE, MDA, or aldehyde-protein adducts; retinoic acid pathway studies can detect retinaldehyde and retinoic acid. Such detection is closer to metabolic flux analysis, but has higher requirements for sample handling and analytical platforms.

6 Experimental Design in ALDH Detection

6.1 Sample Types

(1) Cell samples

Cell samples are suitable for drug treatment, gene knockdown, overexpression, oxidative induction, and cell subpopulation analysis. When detecting enzyme activity, cell density, treatment time, and lysis conditions should be controlled, and repeated freeze-thaw cycles or strong detergents that may destroy enzyme activity should be avoided.

(2) Tissue samples

The liver, myocardium, brain, kidney, and gastrointestinal tract are common tissues in ALDH research. Tissue homogenates should be prepared at low temperature, and sample exposure time should be minimized. If ALDH2 is the focus, mitochondrial fractions or mitochondria-enriched samples can be used for analysis.

(3) Serum and body fluid samples

Serum ALDH activity or related protein levels can be used in some disease and injury studies, but body fluid samples are strongly affected by source, stability, and background proteins. Results should be interpreted together with tissue origin and other oxidative stress indicators.

6.2 Substrate Selection

Substrate selection determines the direction of result interpretation. Acetaldehyde is used for ethanol metabolism, 4-HNE for lipid peroxidation aldehyde detoxification, and retinaldehyde for ALDH1A family-related research. General aldehyde substrates can reflect overall aldehyde oxidation capacity, but cannot directly identify a specific physiological pathway.

6.3 Inhibitors and Positive Controls

ALDH inhibitors can be used to verify signal specificity and can also be used to construct models of impaired aldehyde metabolism. Positive controls can include samples with high ALDH activity or purified enzymes. In flow cytometric detection of cellular ALDH activity, inhibitor controls are especially important for excluding nonspecific fluorescence background.

6.4 Normalization Methods

ALDH activity in tissue and cell lysates is usually normalized by protein concentration and expressed as U/mg protein or relative activity. Flow cytometric analysis can compare the proportion of ALDH-high cells, mean fluorescence intensity, or cell subpopulation percentage. If treatment factors affect cell viability, cell number and viability should also be recorded.

7 ALDH and Common Research Scenarios

7.1 Alcoholic Liver Injury

Acetaldehyde generated from ethanol metabolism is an important toxic intermediate in alcoholic liver injury. Decreased ALDH activity or insufficient ALDH2 function promotes acetaldehyde accumulation and aggravates protein adduct formation, mitochondrial injury, inflammatory responses, and lipid peroxidation. This scenario is suitable for combined detection of ALDH, ADH, acetaldehyde, MDA, GSH/GSSG, ALT, and AST.

7.2 Myocardial Ischemia-Reperfusion

ROS rapidly increase during ischemia-reperfusion, and lipid peroxidation-derived aldehydes also rise. ALDH2 can clear reactive aldehydes in mitochondria and reduce respiratory chain damage and energy metabolism impairment. Combined detection of ALDH2 activity, 4-HNE adducts, MDA, and mitochondrial membrane potential can be used to evaluate myocardial oxidative injury and mitochondrial protective effects.

7.3 Neural Injury and Degenerative Diseases

Neural tissue has high lipid content and active oxidative metabolism, making it prone to formation of lipid peroxidation-derived aldehydes. Insufficient ALDH function increases the risk of protein modification, mitochondrial injury, and neuroinflammation. In neurodegenerative research, ALDH can be detected together with ROS, MDA, 4-HNE, mitochondrial membrane potential, and inflammatory factors.

7.4 Tumor and Drug Resistance Research

High ALDH activity is often used to identify some cancer stem-like cells or drug-resistant cell populations. ALDH1A1, ALDH1A3, and other isoforms may participate in retinoic acid metabolism, oxidative stress tolerance, and drug detoxification. In tumor research, total ALDH activity alone should not be used to infer function; cell phenotype, drug resistance markers, and specific isoform expression should also be analyzed.

7.5 Plant and Microbial Stress Resistance Research

Plants and microorganisms can also generate aldehyde intermediates under salt stress, drought, low temperature, heavy metal exposure, and oxidative stress. ALDH participates in aldehyde clearance and stress resistance responses. For these samples, extraction buffers and detection conditions should be optimized to avoid interference from polyphenols, pigments, and reducing substances.

8 Integrated Analysis of ALDH Detection Results

8.1 Combined Use with Aldehyde Burden Indicators

When decreased ALDH activity is accompanied by increased acetaldehyde, 4-HNE, MDA, or aldehyde-protein adducts, aldehyde generation likely exceeds clearance capacity. When increased ALDH activity is accompanied by decreased aldehyde burden, this is more likely to indicate enhanced compensatory detoxification.

8.2 Combined Use with the Antioxidant Enzyme System

SOD, CAT, and GSH-Px reflect the ROS clearance chain, while ALDH reflects the processing capacity for secondary toxic aldehyde products. Combined detection can distinguish “excess ROS generation” from “insufficient clearance of lipid peroxidation-derived aldehydes,” making it suitable for oxidative stress, drug toxicity, and tissue injury studies.

8.3 Combined Use with Mitochondrial Function

When decreased ALDH2 activity is accompanied by reduced ATP, decreased membrane potential, increased ROS, and abnormal respiratory chain function, mitochondrial aldehyde toxicity and energy metabolism impairment may jointly participate in injury. This combination is suitable for research on myocardial, neural, and hepatic mitochondrial injury.

8.4 Combined Use with Cell Death Indicators

Aldehyde accumulation can induce apoptosis, necrosis, ferroptosis, and inflammatory cell death. ALDH detection can be combined with caspase activity, LDH release, lipid ROS, GPx4, and cell viability indicators to determine whether insufficient aldehyde detoxification has progressed to cellular injury.

9 Product Selection for ALDH Metabolism and Oxidative Stress Detoxification Research

Experimental Step	Cat. No.	Product Name	Grade / Specification	Applicable Scenario
ALDH activity detection	A1515995	Acetaldehyde Dehydrogenase (ALDH) Activity Assay Kit (WST-8, Micro Method)	BioReagent	Evaluation of ALDH activity in cells, tissues, serum, or fermentation samples
ALDH activity detection	A1515994	Acetaldehyde Dehydrogenase (ALDH) Activity Assay Kit (WST-8, Colorimetric Method)	BioReagent	ALDH activity detection on routine colorimetric platforms
ALDH activity detection	A1515803	Acetaldehyde Dehydrogenase (ALDH) Activity Assay Kit (UV Micro Method)	BioReagent	ALDH activity determination in micro-samples and enzymatic analysis
ALDH enzymology research	A1521452	Acetaldehyde Dehydrogenase (ALDH)	Bioactive, Recombinant, ActiBioPure™, High Performance, EnzymoPure™, ≥40 U/mg enzyme powder; ≥200 U/mg protein	Substrate reaction validation, method establishment, and enzyme activity control
ALDH1A1 protein detection	EJ1515060	Human Aldehyde Dehydrogenase 1 Family, Member A1 (ALDH1A1) ELISA Kit	BioReagent	Cancer stem-like cells, retinoic acid metabolism, drug resistance, and oxidative stress research
ALDH1A2 protein detection	EJ1513774	Human Aldehyde Dehydrogenase 1 Family, Member A2 (ALDH1A2) ELISA Kit	BioReagent	Retinoic acid synthesis, developmental regulation, and cell differentiation research
ALDH1A3 protein detection	EJ1513775	Human Aldehyde Dehydrogenase Family 1 Member A3 (ALDH1A3) ELISA Kit	BioReagent	Cancer stem-like cells, drug resistance, and retinoic acid pathway research
ALDH3A1 protein detection	EJ1515061	Human Aldehyde Dehydrogenase 3 Family, Member A1 (ALDH3A1) ELISA Kit	BioReagent	Epithelial tissue, drug metabolism, and oxidative stress defense research
ALDH4A1 protein detection	EJ1515062	Human Aldehyde Dehydrogenase 4 Family Member A1(ALDH4A1) ELISA Kit	BioReagent	Amino acid metabolism, mitochondrial metabolism, and aldehyde metabolism research
ALDH1A1 protein detection	EJ1511963	Rat Aldehyde Dehydrogenase 1 Family, Member A1 (ALDH1A1) ELISA Kit	BioReagent	Rat liver injury, oxidative stress, and drug metabolism models
ALDH2 protein detection	EJ1511964	Rat Aldehyde Dehydrogenase, Mitochondrial (ALDH2) ELISA Kit	BioReagent	Alcoholic liver injury, myocardial ischemia-reperfusion, and mitochondrial aldehyde toxicity research
ALDH protein detection	EJ1512625	Mouse Acetaldehyde Dehydrogenase (ALDH) ELISA Kit	BioReagent	Evaluation of oxidative stress, aldehyde metabolism, and detoxification capacity in mice
ALDH2 protein detection	EJ1512626	Mouse Aldehyde Dehydrogenase, Mitochondrial (ALDH2) ELISA Kit	BioReagent	Mouse ethanol metabolism, myocardial injury, neural injury, and lipid peroxidation models
ALDH4A1 protein detection	EJ1513318	Mouse Aldehyde Dehydrogenase 4 Family Member A1 (ALDH4A1) ELISA Kit	BioReagent	Mouse amino acid metabolism, mitochondrial metabolism, and oxidative stress research
ALDH1A1 immunodetection	Ab088039	ALDH1A1 Mouse mAb	ExactAb™, Validated, Carrier Free, 1.0mg/mL	Western blot, immunohistochemistry, immunofluorescence, and isoform validation
ALDH1A1 immunodetection	Ab184310	ALDH1A1 Mouse mAb	Carrier Free,ExactAb™,Azide Free,Validated,High Performance,PBS Only,≥95%(SDS-PAGE),1.0 mg/mL	ALDH1A1-related cancer stemness, drug resistance, and retinoic acid metabolism research
ALDH1A3 immunodetection	Ab325685	ALDH1A3 Mouse mAb	KO Validation	ALDH1A3 expression validation, cancer stem-like cells, and drug resistance mechanism research
ALDH1B1 immunodetection	Ab327465	ALDH1B1 Mouse mAb	KD Validation	ALDH1B1 isoform function validation
ALDH2 immunodetection	Ab088072	Recombinant ALDH2 Antibody	Recombinant, ExactAb™, Validated, High Performance, See COA	Mitochondrial ALDH2, acetaldehyde clearance, and lipid peroxidation aldehyde detoxification research
ALDH3A1 immunodetection	Ab088079	ALDH3A1 Antibody	ExactAb™, Validated, 1.0 mg/mL	Epithelial tissue, cornea, drug metabolism, and oxidative stress defense research
ALDH3B1 immunodetection	Ab088090	ALDH3B1 Antibody	See COA	ALDH3B1 isoform expression and aldehyde metabolism research
ALDH4A1 immunodetection	Ab327320	ALDH4A1 Mouse mAb	KD Validation	ALDH4A1 functional validation and metabolic pathway research
ALDH6A1 immunodetection	Ab088099	ALDH6A1 Mouse mAb	ExactAb™, Validated, Carrier Free, 0.5 mg/mL	ALDH6A1-related metabolic research
ALDH7A1 immunodetection	Ab088102	Recombinant ALDH7A1 Antibody	ExactAb™, Validated, Recombinant, 1.0 mg/mL	ALDH7A1 isoform expression and aldehyde metabolism research
Recombinant protein	rp175922	Recombinant Human ALDH1A1 Protein	Carrier Free,Azide Free,His Tag,PBS Only,≥95%(SDS-PAGE)	Enzymology research, antibody validation, and methodological control
Recombinant protein	rp329678	Recombinant Human ALDH1B1 Protein	≥90%(SDS-PAGE)	ALDH1B1 functional research and method validation
Recombinant protein	rp330376	Recombinant Human ALDH2 Protein	≥95%(SDS-PAGE)	ALDH2 enzymology experiments, acetaldehyde clearance, and mitochondrial aldehyde toxicity research
Recombinant protein	rp329863	Recombinant Human ALDH9A1 Protein	≥90%(SDS-PAGE)	ALDH9A1-related metabolism and enzymology research
ALDH1A1 inhibition	A288133	A37	≥97%(HPLC)	ALDH1A1 functional validation, cancer stem-like cells, and drug resistance mechanism research
ALDH1A1 inhibition	A648011	ALDH1A1-IN-2	≥99%	ALDH1A1 pathway intervention and functional validation
ALDH1A1 inhibition	A1440382	ALDH1A1-IN-3		ALDH1A1 mechanism research
ALDH1A1 inhibition	A1440379	ALDH1A1-IN-4		ALDH1A1 functional validation
ALDH1A inhibition	A1495484	ALDH1A inhibitor 673A	Moligand™, 10 mM in DMSO	ALDH1A pathway, retinoic acid metabolism, and cancer stemness research
ALDH1A inhibition	C288645	CM 10	≥98%(HPLC)	ALDH1A functional blockade, cell differentiation, and drug resistance research
ALDH1A2 inhibition	A648075	ALDH1A2-IN-1	≥98%	Retinoic acid generation, developmental regulation, and cell differentiation research
ALDH1A3 inhibition	A648564	ALDH1A3-IN-1	≥98%	Cancer stem-like cells, drug resistance, and retinoic acid pathway research
ALDH1A3 inhibition	A647797	ALDH1A3-IN-2	≥99%	ALDH1A3 functional validation and mechanism research
ALDH1A3 inhibition	A1500597	ALDH1A3-IN-3	Moligand™, 10 mM in DMSO	ALDH1A3 pathway intervention
ALDH3A1 inhibition	A651483	ALDH3A1-IN-1	≥95%	Drug metabolism, epithelial antioxidant defense, and ALDH3A1 mechanism research
ALDH3A1 inhibition	A1440383	ALDH3A1-IN-2		ALDH3A1 functional validation
ALDH2 modulation	A303506	Alda 1	≥99%	ALDH2 protective effects, myocardial ischemia-reperfusion, and mitochondrial aldehyde toxicity research
ALDH2 modulation	A1440384	ALDH2 modulator 1		ALDH2 functional regulation and aldehyde detoxification research
Gene intervention	A1476304	ALDH1A1 Human Pre-designed siRNA Set A		ALDH1A1 functional validation, cancer stem-like cells, and drug resistance research
Gene intervention	A1464142	ALDH1A2 Human Pre-designed siRNA Set A		Retinoic acid pathway and cell differentiation research
Gene intervention	A1474376	ALDH1A3 Human Pre-designed siRNA Set A		ALDH1A3-related cancer stemness and drug resistance mechanism research
Gene intervention	A1472903	ALDH2 Human Pre-designed siRNA Set A		ALDH2 acetaldehyde clearance, mitochondrial aldehyde toxicity, and oxidative injury research
Gene intervention	A1489768	ALDH3A1 Human Pre-designed siRNA Set A		ALDH3A1 drug metabolism and epithelial antioxidant research
Gene intervention	A1487100	Aldh1a1 Mouse Pre-designed siRNA Set A		ALDH1A1 functional validation in mouse models
Gene intervention	A1485455	Aldh2 Mouse Pre-designed siRNA Set A		Mouse ALDH2, ethanol metabolism, and mitochondrial injury research
Gene intervention	A1487725	Aldh2 Rat Pre-designed siRNA Set A		Rat alcohol metabolism, myocardial injury, and oxidative stress models
Gene knockout sample	P743731	pLenti-ALDH1A1-sgRNA		Antibody validation, protein expression control, and functional research
Gene knockout sample	P743733	pLenti-ALDH1A3-sgRNA		ALDH1A3 antibody validation and mechanism research
Gene knockout sample	P743735	pLenti-ALDH3A1-sgRNA		ALDH3A1 antibody validation and expression control

Aldehyde dehydrogenase is involved not only in acetaldehyde clearance during ethanol metabolism, but also in the metabolism of lipid peroxidation-derived aldehydes, retinaldehyde, and various endogenous reactive aldehydes. ALDH detection should be selected according to the research objective, including total activity, isoform protein detection, cellular activity flow cytometry, or aldehyde metabolite analysis. It should also be interpreted together with oxidative stress, lipid peroxidation, and cellular injury indicators to accurately evaluate the role of ALDH in aldehyde metabolism and oxidative stress detoxification.