1-Methyl-7-nitroisatoic anhydride (1M7) is a reagent. It detects local nucleotide flexibility, for probing 2'-hydroxyl reactivity.

1-Methyl-7-nitroisatoic anhydride RNA shape and structure processing experiment
a. Preparation of solutions and samples:
1. Solution preparation:
1.1 Mother solution preparation: Prepare a certain concentration of 1M7 mother solution, store it at -20℃ or -80℃ in the dark after aliquoting.
1.2 Working solution preparation: Select the appropriate working solution concentration according to the experimental requirements, such as diluting it into a 1M7 working solution with a concentration of 80 mM, and try to prepare it before use.
2. Preparation of sample RNA:
RNA should be dissolved in RNase-free water or 0.5× TE buffer pH 8.0 at a concentration of 5 μM, and aliquot and store at −20 °C.
b. Operation steps:
1. 1 μL 80 mM 1M7 + 9 μL RNA, mix quickly by pipetting and incubate at 37 °C for 3 minutes. The incubation time of the 1M7 reagent depends on the temperature and pH of the system being studied. Incubation time will be longer at lower temperatures and more acidic pH values.
2. Ethanol precipitation. Add 90 μL RNase-free water, 4 μL 5 M NaCl, 1 μL glycogen (20 mg/mL), and 240 μL ethanol to the mixture. Stir well. Incubate at −80°C for 30 minutes.
3. Centrifuge at maximum speed in a microcentrifuge at 4°C for 30 minutes before subsequent primer extension experiments.