Silver: Plasmid Verification

Growing up more plasmid DNA

1. Touch a sterile plastic pipet tip to chosen colony (only one colony!).
2. Dip then swish tip in 5 mL LB media containing 5 µL Amp (100 mg/mL in distilled water) in a 14 mL tube.
3. Shake the tube at 37 °C for 12-16 hrs.
4. Use Qiagen's Spin Mini-prep kit to mini-prep the vector from the culture.
   • The typical yield from a 5 mL culture is ~35µL of ~150ng/µL or ~5µg.

Analytical Digestion and Gel of Biobricks Part

• If the insert is greater than 200 bp in length, then digest with the enzyme pair that you initially used to install the part into the BioBricks vector (see digestion).
• If the insert is less than 200 bp, use ApaLI and a second enzyme (EcoRI, SpeI, etc.,) such that your fragment of interest is ~300-600 bp. Note: the basic protocol is the same as below, except replace XbaI and PstI with ApaLI and EcoRI (or SpeI, etc).
  • Mix:
    • 3 µL mini-prepped DNA (~100 ng DNA)
    • 1 µL 10x BSA
    • 1 µL 10x NEB Buffer 3 (assuming digestion with XbaI and PstI; otherwise select other appropriate buffer (see NEB website)
    • 0.1 µL XbaI (only 1-2 units are required)
    • 0.1 µL PstI (only 1-2 units are required)
    • distilled water to bring to 10 µL total volume
  • Run a 1-2% agarose gel to check for the presence and size of the insert.

Sequencing of Biobricks Part

• (Only sequence new parts, final devices, and useful intermediates.)
  1. For each sequencing reaction, submit ~ 600 ng of plasmid DNA and 3.2 pmol of the appropriate primer.
     • To confirm the entire sequence of the BioBricks part, both forward and reverse sequencing should be done.
  2. Submit labeled tubes to the DFCI molecular biology core.

Archiving the New Part

• All new parts should be stored in the Silver Lab plasmid collection and strain collection. It is also helpful to keep parts that you have made in your personal strain collection.
• For the plasmid collection, place 5 uL mini-prepped plasmid DNA in a labeled eppendorf tube in the appropriate plasmid collection freezer box in the -20 freezer in Sm920.
• For the strain collection, grow a bacterial culture either to mid-exponential phase or overnight. Mix equal volumes 50% glycerol and culture in an autoclaved 2 mL screw-top tube. Quick freeze the mixture by immersing in liquid nitrogen. Store at -80.