1.     Start overnight with 2-3ml of LB
                    2.     Add 1-2ml of overnight into 100ml LB
                    3.     Incubate and shake at 200 rpm
                    4.     Grow to an OD₅₅₀ of about 1
                    5.     Aliquot culture into two separate (sterile) 50ml tubes
                    6.     Let stand on ice for 20 minutes
                    7.     Make 0.1 M CaCl₂ and put on ice
                    8.     Centrifuge in swing bucket at 3500 rpm, 10 min, 4oC
                    9.     Pour off supernatant
                    10.   Resuspend pellet in 16ml of 0.1 M CaCl₂ per 50 ml culture
                    11.   Ice for 30-60 min
                    12.   Centrifuge at 3500 rpm, 10 min, 4^oC
                    13.   Pour off supernatant
                    14.   Resuspend pellet in 2-4 ml ice cold CaCl₂ per tube.
                    15.   Repeat step 12-14 two or three times  On the final repeat only add 1-2ml of CaCl₂
                    16.   (Optional) let age 24hrs
                    17.   If making glycerol freeze add 1ml 80% glycerol for every 4ml CaCl₂ suspended cells. Pre-chill tubes