E coli 2013

Week before lab:

• streak out control cells on agar plate

• grow overnight at 37C

• cover plate and refrigerate

Two days before lab:

• pick colony, put into enough LB for all students (~250 mL)

• grow on shaker overnight

Day before lab:

• put LB in fridge

  • need ~15 mL
  • 2013 - have lots of 25 mL tubes of LB. Use them up

• check during day for stasis (OD = ~2.6 in previous years; growth seems to stop at OD = ~2, which is still in the linear range)

NOTE: If left too long on shaker, get too many in chains. Check culture first thing in the morning with microscope. OD = 2, still swimming. Put in fridge.

• refrigerate to stop growth

• Dilute or spin down and resuspend to OD = ~2.5 (around max linear correlation to conc) with ice cold LB

• Aliquot ~4 mL/tube

• 1 tube per pair