E coli 2013

Submitted by kdorfman on Wed, 09/11/2013 - 16:15

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