Steps: prompt: (1) Add the specified amount of absolute ethanol to the rinse RW bottle before using it for the first time! (2) Add β-mercaptoethanol to the lysate RLT before the operation to a final concentration of 1%, such as 10 μl of β-mercaptoethanol in 1 ml of RLT. This lysate is preferably used now. With a good RLT 4 ° C can be placed for one month. 1. Direct grinding method (recommended): a. Fresh plant tissue is weighed and taken 100mg and quickly cut into small pieces into a mortar (freeze or liquid nitrogen preservation sample can be directly weighed, take 100mg into the mortar), add 10 volumes (1ml) RLT (please confirm The β-mercaptoethanol has been added and 1 volume (100 μl) of PLANTaid is thoroughly ground to homogenate at room temperature, taking care that the tissue and the lysate RLT should be rapidly contacted immediately to inhibit RNase activity. b. Transfer the lysate into a centrifuge tube, shake vigorously for 15 seconds, centrifuge at 13,000 rpm for 5-10 minutes, precipitate non-cleavable fragments and PLANTaid combined with polysaccharide polyphenols, take 450 μl of lysate supernatant to a new centrifuge tube. c. Add half of the absolute ethanol (0.5 volume), precipitation may occur at this time, but does not affect the extraction process, immediately mix and mix, do not centrifuge. d. Immediately follow the steps in step 3. 2. Liquid nitrogen grinding method: a. Take 500 μl of lysate RLT (already added β-mercaptoethanol), transfer to a 1.5 ml centrifuge tube, add 50 μl of PLANTaid and mix for later use. b. After grinding the appropriate amount of plant tissue into fine powder in liquid nitrogen, 50 mg of fine powder was transferred to the above-mentioned centrifuge tube containing RLT and PLANTaid, and immediately shaken vigorously by hand for 20 seconds to fully lyse. Incubation at 56 ° C for 1-3 minutes helps to lyse the plants, but plants with high starch content cannot be incubated because elevated temperatures may cause starch to swell. c. Dip the lysate 10 times with a disposable 1 ml (with a 0.9 mm needle) syringe with a blunt needle or until a satisfactory homogenization result (or motor homogenization for 30 seconds) can be used to shear the DNA, reduce viscosity and increase Yield. d. Centrifuge the lysate at 13,000 rpm for 5-10 minutes to precipitate undecomposable fragments and PLANTaid combined with polysaccharide polyphenols. Transfer all lysate supernatant to a new centrifuge tube. e. Accurately estimate the volume of the lysate (supernatant), add 0.5 volume of absolute ethanol, precipitation may occur at this time, but does not affect the extraction process, immediately mix and mix, do not centrifuge. f. Immediately follow the steps in step 3. 3. Add the mixture (less than 700 μl each time, can be added in two portions) to an adsorption column RA (the adsorption column is placed in a collection tube) and centrifuge at 13,000 rpm for 60 seconds to discard the waste liquid. 4. Add 700 μl of deproteinized solution RW1, leave it at room temperature for 30 seconds, centrifuge at 12,000 rpm for 30 seconds, and discard the waste. If the DNA residue is obvious, it can be centrifuged for 5 minutes after adding RW1 at room temperature. 5. Add 500 μl of rinse RW (check to see if absolute ethanol has been added!), centrifuge at 12,000 rpm for 30 seconds, and discard the waste. Add 500 μl of rinse RW and repeat. 6. Place the adsorption column RA back into the empty collection tube and centrifuge at 13,000 rpm for 2 minutes to remove the rinse solution as much as possible to prevent residual ethanol in the rinse solution from inhibiting the downstream reaction. 7. Remove the adsorption column RA and place it in an RNase free centrifuge tube. Add 30-50μl RNase free water to the middle of the adsorption membrane according to the expected RNA yield (previously heated in a 70-90 °C water bath), room temperature Centrifuge at 12,000 rpm for 1 minute in 1 minute. 8. If the expected RNA yield is >30μg, repeat step 7 with 30-50μl RNase free water, combine the two eluents, or use the first eluent to add back to the adsorption column and repeat the step once (if the RNA concentration is high) ). The concentration of the RNA eluate eluted twice was high, and the RNA yield of the eluate was 15–30% higher than that of the former, but the concentration was low, and the user selected it as needed. FFP2 Mask,Particulate Respirator,FFP2 Particulate Respirator,Particle Filtering FFP2 Respirator Henan Aklly Filter Engineering Co., Ltd , https://www.akllyfilter.com