Team:University College London/LabBook/Week4

Step 1 - Addition of BioBrick: To the still frozen competent cells, add 1 - 5 µL of the resuspended DNA to the 2ml tube.

Step 4 - Incubation: Close tube and incubate the cells on ice for 45 minutes.

Step 5 - Heat Shock: Heat shock the cells by immersion in a pre-heated water bath at 37ºC for 10 minutes.

Step 6 - Incubation: Incubate the cells on ice for 2 minutes.

Step 7 - Add media: Add 1.5ml of Lysogeny Broth and transfer to a falcon tube.

Step 8 - Incubation: Incubate the cells at 37ºC for 1 hour at RPM 550. 

Step 9 - Transfer: transfer the solution back into a 1.5ml Eppendorf and centrifuge

RPM: 14000

Time: 2 minutes

Temperature (18-25oC)

Step 10 - Resuspend:Remove supernatant and resuspend in 100ul LB

Step 11 - Plating: Spread the resuspended cell solution onto a selective nutrient agar plate. Place the plates in a 37°C static incubator, leave overnight (alternatively a 30°C static incubator over the weekend)

Step 1 – Creating culture media: In a sterile environment, set up X numbers of falcons, each with 5mls of media.

Step 2 - Inoculating Colonies into a Selective Broth:: Add Yul of antibiotic to reach desired antibiotic concentration.

(For Ampicillin this is 50ug/ml, For Kanamycin it is 25ug/ml, for Tetracycline it is 15ug/ml, and for Chloramphenicol it is 25ug/ml)

Step 4 – Selecting a Colony: Select a clear, isolated colony and using an inoculation hoop scoop up a colony onto the tip. Deposit in the falcon tube

Step 5 - Culture: Culture your falcon tubes overnight at a temperature of 37 oC. Leave for no longer than 16 hours.

Step 1 - Pellet Cells: Pellet 1-5ml bacterial overnight culture by centrifugation at >8000rpm (68800 x g) for 3 min at room temperature (15-25oC)

Step 2 - Resuspend Cells: Resuspend pelleted bacterial cells in 250ul Buffer P1 and transfer to a microcentrifuge tube

Step 3 - Puncturing Cell Membrane: Add 250ul Buffer P2 and mix thoroughly by inverting the tube 4-6 times until the solution becomes clear. Do not allow the lysis reaction to proceed for more than 5 min.

Step 4 - Neutralising buffer P2: Add 350ul Buffer N3 and mix immediately and thoroughly by inverting the tube 4-6 times.

Step 5 - Centrifuge:

RPM: 13000

Time:10 minutes

Temperature: 18oC

Step 6 - Centrifuge: Apply the supernatant from step 5 to the QIAprep spin column by decanting or pipetting. Centrifuge for 30-60s and discard the flow-through.

Step 7 - Remove Endonucleases from Sample: Wash the QIAprep spin column by adding 500ul of Buffer PB. Centrifuge for 30-60s and discard flow-through.

Step 8 - Remove salts from sample: Wash the QIAprep spin column by adding 750ul of Buffer PE. Centrifuge for 3-60s and discard flow through.

Step 9 - Centrifuge:

RPM: 13000

Time:1 minute

Temperature: 18oC

Step 10 - Elute DNA: Place the QIAprep column in a clean 1.5ml microcentrifuge tube. To elute DNA, add 50ul Buffer EB to the centre of the spin column, let it stand for 1 min, and centrifuge for 1 min.