1. Prewarm LB+antibiotic plates at 37° C.
2. Remove competent cells from –80° C freezer and thaw on ice.
3. As soon as cells are thawed, immediately add 1-10ng DNA per 100ul of cells.
4. Incubate on ice for 5 minutes.
5. Spread cells on plates (100ul on one, 20-50ul on another).
6. Incubate at 37° C overnight.
Competent Cells
We currently have three types of competent cells:
1. DH5α- general use
2. XL10-Gold – large or ligated DNA
3. XL1-Blue – unmethylated DNA; unlimited DNA or subcloning