| Message: | Receptive state is a special physiological state in which cells (or bacteria) can absorb DNA molecules from the surrounding environment and are not easy to be decomposed by restriction endonucleases in cells. Some bacteria are naturally susceptible, such as Bacillus subtilis, and some are artificially susceptible, such as Escherichia coli. After special treatment, receptor cells can change the permeability of cell membrane and become competent cells that allow the carrier molecules of exogenous DNA to pass through.
The raw material of TB solution -- pipe powder
Transformation buffer preparation:
Piperazine diethyl sulfonic acid 3.0g 10mm, CaCl2 · 2H2O 2.2g 15mm, KCl 18.6g 250mm were prepared. 950ml water was added, pH was adjusted to 6.7-6.8 * with 5N Koh, insoluble at low pH, and then 10.9g MnCl2 · 4H2O with final concentration of 55mm was added to 1 L, filtered and sterilized, and stored at 4 ℃. |
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