Transformation

Procedure (for E. coli XL2-Blue)

Obtain an ependorff of competent cells
Place the cells on ice and let them thaw on ice (about 10-15 minutes)
Gently stir the cells with a pipette tip to resuspend them
Pipette 50 ul of cells into an ependorff
With gentle stirring, pippette 5 ul of a 20 ul ligation reaction into the ependorff
Place the ependorff on ice for at least 30 minutes
Put the competent cells back at -70*C (remember to mark your ependorff so you know which is yours)
Prepare the heating block for 42*C
Heat shock the transformation mixture for 45 seconds at 42*C
Put the transformation mixture on ice for 2 minutes
Add 400 ul of sterile YT to the transformation mixture
Mix gently by inverting several times
Incubate at 37*C for at least 45 minutes
Centrifuge at full speed for 2 minutes
Discard 300 ul of the supernatant
Resuspend the pellet in the remaining 150 ul
Plate and incubate at 37*C overnight