In vitro transcription of guide RNAs
No PCR cleanup necessary at this point.
Incubate transcription mix for ~18 hours at 37˚ in a thermalcycler. 
Add 1 µl of RNase-free DNase; incubated 20 min, room Temp.  
Bring volume to 150 uL with 100% EtOH (this helps binding of small fragments). 
Add 5X SPRI (we use homemade SeraPure beads for RNA binding) 5*10 (IVT sgRNA) = 50 uL of SPRI Beads5*20 (IVT sgRNA) = 100 uL SPRI Beads.  
Pipette to mix 10 times Incubate 5 minutes at room temperature.  
Place on magnetic stand, 5 min. 
Discard supernatant. 
Wash#1 Add 200 uL, 80% EtOH.
Wait 2 min.
Remove EtOH.
Wash #2: Add 200 uL, 80% EtOH.
Wait 2 min.
Remove EtOH.
Air dry 5-10 min (pellet will change from a glossy/wet to matte/dry. )
Elute 20 uL of water or TE.
Pipette mix 10 times.
Incubate 2 minutes at room temperature. 
Place on magnetic stand, 5 min. 
Keep Supernatant.
Transfer to a new plate / tubes.
