Matt:LabNotes/2014-1-15
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Exo I/III in situ to check 2ndary Rolony Ampligase reaction
- Currently 2nd Rolony fabrication is inefficient or unsuccessful
- Need a positive and negative control (currently working on making positive control by pre-circularizing ppMALAT1)
- Trying to determine whether Ampligase reaction or 2nd RCA is the limiting step
- How to separate Ampligase step from 2nd RCA step?
- Add Exo I/III to cells after Ampligase step to digest non-circular DNA
- Then can use Shifted FISSEQ_2ndRCAprimerDye to detect the padlock probes that are left (and therefore circularized)
- By using positive and negative control, can determine yield of Ampligase step
Procedure
- Use 6 wells with 1st Rolonies from 96-well plate:
- 2 Positive control: +Ampligase, -Exo (expect to see lots of signal like previous experiments)
- 2 Negative control: -Ampligase, +Exo (expect to see no signal)
- 2 Experimental: +Ampligase, +Exo (expect to see a % of a positive control, hopefully close to 100%)
Determine Number of ppMALAT1 targets
- Hybridize 2pM ppMALAT1 (in 2X SSC)
- Preheat to 70C for 5min and then add 50ul to each well
- Incubate 50C for 10min
- Wash once with 2X SSC
- Add 2uM Shifted FISSEQ_2ndRCAprimerDye in 30% formamide and 2X SSC
- Preheat to 60C for 5min and then add 50ul to each well
- Incubate RT for 15min
- Wash 2 times with 2X SSC
- Image (ATTO488)
- Strip with 80% formamide for 30min
Ampligase Experiment
- Hybridize 2pM ppMALAT1 (in 2X SSC)
- Preheat to 70C for 5min and then add 50ul to each well
- Incubate 50C for 10min
- Wash once with 2X SSC
- Add 0.05U/ul Ampligase to Positive and Exprimental (2ul Ampligase + 20ul 10X Buffer + 178ul H2O)
- Negative control: (90ul H2O + 10ul 10X buffer)
- Incubate 50C for 4hrs
- Wash twice with 1X PBS
- Add 2.5ul Exo I and 2.5ul Exo III to Negative and Experimental
- Positive control: add 5ul H2O to each well
- Incubate 37C for 2hrs
- Wash twice with 1X PBS preheated to 94C
- Let sit for 1min before aspirating
- Add 2uM Shifted FISSEQ_2ndRCAprimerDye in 30% formamide and 2X SSC
- Preheat to 60C for 5min and then add 50ul to each well
- Incubate RT for 15min
- Wash 2 times with 2X SSC
- Image (ATTO488)