Transforming Cells

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Transformation typically requires expensive equipment and storing competent cells is difficult for many high schools who do not have -80oC freezers. We tried a few methods of transforming cells and making them competent to attempt to solve this problem in our kit.

TSS Transformation Protocol

The TSS transformation protocol was tested. The procedure is listed here.

  • Acquisition of reagents- June 3, 2010
  • Preparation of buffer - June 7, 2010
  • Cell preparation - June 7, 2010
  • Protocol trial - June 10, 2010
  • Assessment of efficiency - June 11, 2010

Results: Transformation with pSB1C3 gave a transformation efficiency of 4.8*10^7 colonies/μL. All colonies on the plate were strongly pink, as expected. Preparation of the cells took only 120 minutes, with a single transformation taking 90 minutes. On the other hand, a typical stock Inoue transformation cells takes a full day of work, with a single transformation taking about 120 minutes.

Rubidium chloride competent cells and lyophilization

This method was adapted from a competent cell protocol found here, which was suggested to us by former iGEM team member Justin Fedor. A small modification to include 200mM of sucrose in each of the transformation buffers. The cells were then lyophilized overnight at 4°C on a FTS Systems Dura-Dry Lyophilizer.

  • Preparation of transformation buffer - July 6, 2010
  • Preparation of cells - July 10, 2010
  • Preparing competent cells - July 11, 2010
  • Lyophilization - July 13, 2010
  • Transformation of FD cells - July 14, 2010
  • Preparation of cells 2 - July 30, 2010
  • Lyophilization - August 2, 2010
  • Transformation - August 5, 2010


Lyophilization proved to greater impair transformation efficiency. The determined transformation efficiency was found to be a 2*10^-1 colonies/μg.