From 2007.igem.org

Miniprep Protocol

Calculate the approx. S/N ratio of the transformation.

Decide on number of tries to be setup accordingly. Pick 12 tries if the S/N ratio is good (5:1), more otherwise.

Aliquot X ml (X = Y number of tries * 3.5, where Y = number of tries.) of TB into a clean (autoclaved) beaker or flask. Lb can be used if TB is not available.

Add X µl of appropriate antibiotic, i.e. a 1:1000 dilution to the above solution. The correct antibiotic should be added (same as the plate from which the colonies are picked.)

Take Y clean and autoclaved 14 ml polystyrene tubes (ones with thw white cap) and place them on a rack. Label them clearly. Aliquot 3.5 ml of TB/LB into each 14 ml tube.

Use a sterile wooden applicator (autoclaved) or pipette tip to carefully pick an individual colony and dip the colony end of the applicator / tip into a 14 ml tube. Repeat this Y times using a fresh applicator each time. Make sure to pick a single colony per try.

Place the tubes in the 37C shaker at 280-300 rpm and grow the cells for 12-14 hours. The tubes should be murky after the overnight growth.