Team:Imperial College London/Project/Chemotaxis/Protocols
From 2011.igem.org
27th of July
The strain of E. coli with the copy of super-folded GFP that was incubated the previous night has shown limited/no growth in the prepared LB broth. This could have been caused by:-No innoculation
-Kanamycin concentration in LB broth was too high. We had used 85μg/ml.
New protocol:
50μg/ml is the recommended concentration. We will use 35-40μg/ml of kanamycin to speed up growth.
28th of July
Transformation of cells with 6, 7 and 8:-Let competent cell strain 5α thaw for around 10 minutes on ice.
-Add 2-3μl of DNA.
-Leave on ice for 20-25 minutes.
-Heat shock cells at 42°C for 45 seconds.
-Leave on ice for 10 minutes.
-Add 500μl of LB broth.
-Incubate for 1 hour at 37°C.
-Centrifuge for 1 minute.
-Remove 100μl off the top of the eppendorf tube. Pour out the rest making sure that the pellet remains in the eppendorf tube.
-Re-suspend the cells in the 100μl LB broth solution that was removed in the previous step. -Add 5μl on a chloramphenicol agar plate (concentration of 35μg/ml).
-Add the rest of the sample to a second chloramphenicol agar plate.
28th of July
To make tryptone broth (bacterial growth before chemotaxis assays)for total volume of 1L:
-10g tryptone
-1000ml of 1X PBS
-autoclave
-1.14g kanamycin
To make 1X PBS (phosphate buffer saline):
-in 800ml of distilled H2O
-8g of NaCl
-0.2g of KCl
-1.44g of Na2HPO4
-0.24g of KH2PO4
-adjust pH to 7.4
-adjust volume 1L with additional distilled H2O
-autoclave
Note: also possibility to use 1X PBS tablets (one tablet per 200ml)