Golden Gate Assembly for Bio113
Starting with Boiled then Cooled Oligos
- You should have already used the Oligator to design your oligos for your dsDNA promoter.
- You should have already calculated how to dilute your boiled and cooled oligos from 5 µM to 40 nM.
If you didn't take the time to calculate the dilution, you can use this shortcut as an approximation:
- 1 µL cooled oligos.
- 99 µL water to make a 100X dilution.
- Use 1 µL of the 100X diluted oligos and add to the 9 µL described below.
Protocol Details for GGA
- You will be given two tubes. One tube will be labeled "P" for promoter ligation, the other "-" for the negative control of plasmid only. Put your initials on the tubes and return the tubes to ice. These tubes will already contain 9 µL of the GGA Mixture.
- Add 1 µL diluted oligos cooled overnight to the tube labeled P for "GGA promoter".
- Add 1 µL water to the tube labeled - for "GGA negative control"
GGA mixture contains:
1 µL (40 nM) plasmid containing part J119137 which is 3671 bp in size
6 µL dH2O
1 µL 10X Promega Ligase Buffer
0.5 µL Bsa I high fidelity (HF) restriction enzyme
0.5 µL T4 DNA ligase from Promega
9 µL final volume
Turn on the PCR machine. Put both of your tubes into the machine.
Program it for the following cylces:
- 20 cycles of 37C for 1 minute/16C for 1 minute
- 1 cycle of 37C for 15 minutes
- 22C holding temperature
This DNA ligation is ready for transformation.
You can increase the number of cycles to 30 if you want to increase yield. However, we have gotten good success with as few as 5 cycles.
Transformations after GGA
You want to do 3 transformations:
- a positive control that contains known PlacI + RBS + RFP to be used for comparison RFP expression.
- your experimental GGA ligation
- your negative control "GGA plasmid only" ligation.
Pipet 40 µL of Zippy competent cells into each of three 1.5 mL tubes labeled appropriately for each of the three transformations listed above. Plate all three transformations (with SOC) on LB amp plates.
PCR Verification of Successful GGA
If you want to PCR verify that GGA has happened, you can use colony PCR and analyze the product by gel electrophoresis (1.7% agarose gel).
- Use negative control colonies as template to see the MW of the PCR product when TT is still in the plasmid and no GGA has occurred. Run one lane of this negative control PCR product for each row on your gel.
- Use these two primers:
- Forward = 5’ GAATTCGCGGCCGCTTCTAG 3’
- Reverse = 5’ TTTGATAACATCTTCGGAGG 3’
- PCR product with the original TT still in place is 251 bp
- size of TT that should be removed by GGA is 107 bp
This protocols was developed at MWSU by Dr. Todd Eckdahl, and modified at Davidson College by Annie Wacker and Malcolm Campbell.