Contents
Preparation of CaCl2 competent cells
- Dilute 500μl of overnight liquid culture into 20ml of broth with any necessary antibiotics to select for any plasmids already transformed into the cells.
- Incubate at 37⁰C, shaking at 225rpm for 105 minutes.
- Spin down for 2 minutes at 7000G at 4⁰C.
- Discard supernatant, resuspend pellet in 10ml of 50 mM CaCl2, keep on ice.
- Repeat centrifugation for 2 minutes at 7000G at 4⁰C.
- Discard supernatant and the resuspend pellet in 1ml of 50 mM CaCl2, keep on ice.
- CaCl2 competent cells can be kept on ice in the fridge overnight.
Transformation of CaCl2 competent cells
- Add 1μl of plasmid DNA to 100μl of competent cells.
- Heat shock at 42oC for 45 seconds.
- Add 200μl of L-broth of the sample.
- Keep on ice for 2 minutes.
- Incubate the cells at 37oC. The time varies depending on which antibiotic resistance the plasmid holds.
Aims
- Aim 1
- Sub-aim 1
- Sub-aim 2
- Aim 2
- Sub-aim 1
- Sub-aim 2
Materials and Methods
Condition set up
Sample preparation
- 1
- 2
- 3
Table 1: Optical density analysis of S. thermophilus growth
Results and Discussion
Outlook
References
- ↑ Kiliç, A. O., Pavlova, S. I., Ma, W. G. & Tao, L. 1996. Analysis of Lactobacillus phages and bacteriocins in American dairy products and characterization of a phage isolated from yogurt. Appl Environ Microbiol, 62, 2111-6.
