2025.08.22
Crime Scene:
Lab Unsolved Mystery: "Compound X is Ames-negative → Safe!"
Reality: Clinical DNA damage in patients → Project halted! Who's the culprit?
Stealthy Toxicants:
Metabolically inert compounds appear harmless but transform into "DNA saboteurs" in vivo.
Don't panic—90% of cases lack a critical tool: Metabolic Activation via Induced Liver S9!
Introducing the Star—Induced Liver S9:
The "Sherlock Holmes" of genotoxicity testing, the ultimate metabolic enhancer:
1.High Enzyme Activity: Double-induced by phenobarbital + β-naphthoflavone. Full activation of CYP1A, 2B, 3A pathways.
2.Dual Species Coverage: Available in SD Rat and Golden Hamster versions. Meets ICH M7 guideline requirements for "rat + hamster" metabolic systems.
3.Ready-to-Use: 30mg/mL concentration, sterile-filtered. Includes QC report (CoA) → Zero protocol errors.
4.Compliance Guaranteed: Every batch validated with classic mutagen 2-aminofluorene. Only released if mutagenic response ≥2-fold.
Case-Solving Toolkit
Characteristics | Conventional S9 | Induced S9 |
Metabolic Activity | Baseline (low) | CYP superactivation |
Detection Sensitivity | Limited resolution | High-resolution screening |
False-Negative Rate | >30% | Dramatically reduced |
Three Classic Case Studies
Case 1: The "Perfect Crime" of Polycyclic Aromatic Hydrocarbons
Culprit: Benzo[a]pyrene (BaP)
▲ Conventional S9: TA98 strain → 0 mutations (False Negative
▲ Induced S9: CYP1A1 activation → Generates 7,8-dihydrodiol-9,10-epoxide → TA98 revertants **↑15-fold!**
Case 2: The "Dual Identity" of Aromatic Amines
Culprit: 2-Aminoanthracene (2-AA)
Trap: Requires N-acetylation for toxicity.
▲ Induced S9 Advantage: Co-activates CYP1A2 + NAT enzymes → TA1538 revertant colonies **↑3× vs. control!**
Case 3: The "Flash Kill" by N-Nitrosamines
Culprit: NDMA (N-Nitrosodimethylamine)
▲ Conventional Limitation: Only detectable with hamster S9.
▲ Induced S9 Solution: Enhanced CYP2E1 pathway → Generates methyl radicals → TA100 mutation rate **↑8-fold!** (Matched hamster data)
Why Induced S9 is the Gold Standard in Genotoxicity Testing?
Three Key Advantages
1.Metabolic Superconductor:Phenobarbital activates CYP2B/3A; β-Naphthoflavone induces CYP1A.
2. Stealth Toxin Radar: Detects DNA adducts at<0.1% abundance.
3. False-Negative Eliminator:Forces "metabolically lazy" carcinogens to reveal themselves!
Milecell Bio Induced Liver S9 Products
Catalog No. | Product Description | Specification |
1mL × 30mg/mL | ||
3mL × 30mg/mL | ||
1mL × 30mg/mL | ||
3mL × 30mg/mL |
Customized S9 from other species/strains available upon request.
References
[1] Hakura A, et al. Use of human liver S9 in the Ames test... Regul Toxicol Pharmacol. 2003.
[2] Shimada T, et al. Metabolism of benzo[a]pyrene... Chem Res Toxicol. 1999.
[3] Li X, et al. Revisiting the mutagenicity of N-nitroso propranolol... Regul Toxicol Pharmacol. 2023.
[4] Cox JA, et al. The utility of metabolic activation mixtures... Mutagenesis. 2016.
