Synthesize 5' capped transcripts
Synthesize 5' capped transcripts
Some RNA transcripts require an m7 G(5')Ppp(5')G cap at the 5' end, and they have higher translational efficiency only in cell-free extracts or in African Xenopus oocytes. Transcripts with methylated caps have also been reported to have higher efficiency during in vitro shearing and greater resistance to nuclease in nuclear extracts
Operation method
Synthesis of 5' plus cap transcripts
Materials and Instruments
DEPC-treated water Transcription buffer lOOmmol LDTT RNasin rATP rCTP rUTP rGTP0.5 mmol L m7 G(5')ppp(5')G DNA template RNA sample buffer RNA load buffer MOPS buffer TE buffer Move I Materials and equipment For more product details, please visit Aladdin Scientific website.
1) DEPC: Treated water
2) Transcription buffer (5X):200 mmol/LTris-HCI(pH7.9),30 mmol/LMgCl2,lOmmol/L. spermidine,50 mmol/LNaCl
3)lOOmmol/LDTT
4)RNasin
5)rATP, rCTP, rUTP, 2.5 mmol/L each
6)rGTP0.5 mmol/L
7) m7 G (5')ppp(5')G,5 mmol/L
8)DNA template, 1~2 mg/ml
9)RNA sample buffer: 10 mmoL/I. deionized formamide, 3.5 ml37% formaldehyde, 2 mlMOPS buffer
buffer
10) RNA loading buffer: 50% glycerol, lmmol/LEDTA, 0.4% bromophenol blue, lmg/ml ethidium bromide.
11)MOPS buffer: 0.2 mmol/LMOPS(pH7.0),50 mmol/L sodium acetate,5 mmol/LEDTA(pH8.0)
12)TE buffer
Methods
1) In vitro transcription to generate RNA
In a sterile centrifuge tube, add the following ingredients at room temperature.
5X Transcription Buffer 4ul
100 mmol/LDTT 2ul
RNasin 20U
rATP,rUTP,rCTP(2,5 mmol/L each) 4ul
GTP(O.5 mmol/L) 2ul
m7 G(5')ppp(5')G(5 mmol/L) 2ul
DNA template (1~2 mg/ml) 1-2ug
Add nuclease-free water to final volume 19ul
2) Start the reaction by adding 1ul of SP6, T7 or T3 RNA polymerase (15~20U/ul).
3) Incubate at 37~40°C for 60 min.
4) Remove the DNA template as described for RNA standard transcription reaction and purify the RNA transcript.
