3-Methyl-2-quinoxalinecarboxylic acid
Based on 1 Customer Validation
3-Methyl-2-quinoxalinecarboxylic acid (MQCA), an important N-oxide reductive metabolite of Quinocetone or Olaquindox, potently inhibits the growth of Chang liver cells through S phase arrest of the cell cycle.
For research use only. We do not sell to patients.
- Purity : 97.65%
- CAS No.: 74003-63-7
- Formula: C10H8N2O2
- Molecular Weight:188.18
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Storage:Powder -20°C, 3 years ; In solvent -80°C, 6 months , -20°C, 1 month
Biological Activity
Description
Chemical Information
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CAS No. 74003-63-7
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Appearance Solid
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Molecular Weight 188.18
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Formula C10H8N2O2
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SMILES
O=C(C1=NC2=CC=CC=C2N=C1C)O
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Synonyms
MQCA
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Shipping
Room temperature in continental US; may vary elsewhere.
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Storage
Powder -20°C 3 years In solvent -80°C 6 months -20°C 1 month
Solvent & Solubility
In Vitro:
DMSO : 50 mg/mL (265.70 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)
In Vivo:
Select the appropriate dissolution method based on your experimental animal and administration route.
- For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
- To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
- The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.
Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)
Solubility: ≥ 2.5 mg/mL (13.29 mM); Clear solution
This protocol yields a clear solution of ≥ 2.5 mg/mL (saturation unknown).
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (25.0 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C, storage for one week): 2 g SBE-β-CD powder is dissolved in 10 mL Saline, completely dissolve until clear.
In Vivo Dissolution Calculator
Please enter the basic information of animal experiments:
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Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.
Please enter your animal formula composition:
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%DMSO +
Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
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%+
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+%Tween-80 + +
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%Saline +
The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).
Working solution concentration: 0.22 mg/mL
Method for preparing stock solution: mg drug dissolved in μL DMSO. Stock solution concentration: mg/mL.
1. Take μL DMSO stock solution;
2. Add μL .
μL , mix evenly;
3. Then add μL Tween 80, mix evenly;
4. Then add μL
Please ensure that the stock solution in the first step is dissolved to a clear state, and add co-solvents in sequence. You can use ultrasonic heating (ultrasonic cleaner, recommended frequency 20-40 kHz), vortexing, etc. to assist dissolution.
Protocols
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EdU Incorporation Assay (Click Chemistry-Based DNA Synthesis Measurement)
The EdU incorporation assay measures DNA synthesis by adding the thymidine analog 5-ethynyl-2′-deoxyuridine to cells or tissues, where it is incorporated into newly synthesized DNA during S phase. Incorporated EdU is detected by copper-catalyzed azide-alkyne cycloaddition, in which a fluorescent azide covalently reacts with the ethynyl group on EdU, allowing S-phase cells to be detected by fluorescence microscopy, flow cytometry, or high-content imaging. EdU detection does not require DNA denaturation or anti-BrdU antibody access, which preserves sample structure and improves compatibility with immunostaining and multiparameter cytometry compared with BrdU-based detection. EdU can be cytotoxic in a cell-type- and exposure-dependent manner, so pulse duration, concentration, and continuous-labeling designs should be validated for each cell type.
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Flow cytometric DNA-content cell-cycle staining
Flow cytometric DNA-content cell-cycle staining measures the fluorescence intensity of DNA-bound fluorochromes in single cells or nuclei to estimate DNA content distributions, allowing assignment of populations to G0/G1, S, and G2/M phases by DNA histogram deconvolution. Propidium iodide (PI) intercalates into DNA, and PI fluorescence is proportional to cellular DNA content when staining is performed under conditions that make DNA accessible and minimize non-DNA signal. Cells with G2/M DNA content are expected to show approximately twice the fluorescence intensity of G0/G1 cells, while S-phase cells occupy intermediate fluorescence values. PI-based DNA-content analysis can also detect cells with fractional DNA content, often reported as sub-G1, when DNA fragmentation and extraction during staining reduce retained DNA signal in apoptotic cells. DAPI is an alternative DNA fluorochrome for univariate DNA-content analysis, while bivariate approaches combining DNA content with proliferation
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BrdU Incorporation Assay
Bromodeoxyuridine (BrdU) incorporation assay is based on the principle that BrdU, a thymidine analog, is incorporated into newly synthesized DNA during the S phase of the cell cycle, thereby serving as a marker of DNA replication and cellular proliferation. Incorporated BrdU can be detected using anti-BrdU antibodies following DNA denaturation, enabling visualization or quantification of proliferating cells through immunochemical detection methods such as immunofluorescence or immunohistochemistry.
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Protocol for Cell Cycle
Cell-cycle analysis by flow cytometry measures DNA content in single cells to estimate the fraction of cells in G0/G1, S, and G2/M phases. Propidium iodide intercalates into DNA, and after RNA removal with RNase, fluorescence intensity reflects cellular DNA content: 2N cells are assigned to G0/G1, cells between 2N and 4N to S phase, and 4N cells to G2/M. DNA-content analysis alone cannot reliably separate G0 from G1 or G2 from M. Ki-67 can distinguish quiescent G0 cells from cycling cells, EdU or BrdU incorporation marks active DNA synthesis in S phase, and phospho-histone H3 staining identifies mitotic cells within the 4N population.
Purity & Documentation
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Data Sheet (272 KB)
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SDS (393 KB)
- English - EN (393 KB)
- Français - FR (393 KB)
- Deutsch - DE (393 KB)
- Norwegian - NO (393 KB)
- Español - ES (393 KB)
- Swedish - SV (393 KB)
- Italian - IT (393 KB)
- Korean - KR (393 KB)
- Portuguese - PT (393 KB)
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Handling Instructions (2659 KB)
References
Complete Stock Solution Preparation Table
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
| Optional Solvent | Concentration Solvent Mass | 1 mg | 5 mg | 10 mg | 25 mg |
|---|---|---|---|---|---|
| DMSO | 1 mM | 5.3141 mL | 26.5703 mL | 53.1406 mL | 132.8515 mL |
| 5 mM | 1.0628 mL | 5.3141 mL | 10.6281 mL | 26.5703 mL | |
| 10 mM | 0.5314 mL | 2.6570 mL | 5.3141 mL | 13.2852 mL | |
| 15 mM | 0.3543 mL | 1.7714 mL | 3.5427 mL | 8.8568 mL | |
| 20 mM | 0.2657 mL | 1.3285 mL | 2.6570 mL | 6.6426 mL | |
| 25 mM | 0.2126 mL | 1.0628 mL | 2.1256 mL | 5.3141 mL | |
| 30 mM | 0.1771 mL | 0.8857 mL | 1.7714 mL | 4.4284 mL | |
| 40 mM | 0.1329 mL | 0.6643 mL | 1.3285 mL | 3.3213 mL | |
| 50 mM | 0.1063 mL | 0.5314 mL | 1.0628 mL | 2.6570 mL | |
| 60 mM | 0.0886 mL | 0.4428 mL | 0.8857 mL | 2.2142 mL | |
| 80 mM | 0.0664 mL | 0.3321 mL | 0.6643 mL | 1.6606 mL | |
| 100 mM | 0.0531 mL | 0.2657 mL | 0.5314 mL | 1.3285 mL |