Chemical Name: 3-Bromomethyl-6,7-dimethoxy-1-methyl-1,2-dihydroquinoxaline-2-one
Appearance: Yellow needles
Purity: ≥96.0% (HPLC)
MW: 313.15, C12H13BrN2O3
Storage Condition: -20ºC
Shipping Condition: ambient temperature
Br-DMEQ is a highly fluorescent labeling reagent for carboxylates such as fatty acids and prostaglandins. Quinoxalinone compounds are formed by a reaction between 1,2-diamino-4,5-dimethoxybenzene and pyruvic acid. Br-DMEQ also reacts with pyrimidine bases of nucleic acids. Potassium carbonate and 18-crown-6 are necessary for carboxylate labeling with Br-DMEQ. The HPLC detection limit of saturated fatty acids with 3 to 20 carbons is 0.3 to 1 femtomoles per injection. The excitation and emission wavelength of labeled materials are 370 nm and 450 nm, respectively.
DMEQ Labeling Protocol
1. Dissolve a sample with acetonitrile to prepare sample solution.
2. Mix 500 μl of the sample solution, 250 μl of 3.8 mM Br-DMEQ/acetonitrile, and 250 μl of 0.8 mM 18-crown-6/acetonitrile in a reaction vial.
3. Heat the vial at 80ºC for 20 minutes and then cool it in water bath.
4. Use the mixture for HPLC analysis to determine DMEQ-labeled compounds; excitation: 370 nm, emission: 450 nm.
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