Yesterday it occurred to me that I couldn’t autoclave LB media made with DDW or D2O because of D-exchange. So I had to come up with a solution which prompted me to ask the world (thank you internet). Through the power of open science (victory for ONS!) I was able to get some comments that said I should use a 0.2 micron filter:
@Thescienceofant two points 1. you can grow E. coli static (no shaking) 2. why not make(or buy) 10x LB and use sterile-filtered D2O?
— Warren G. Lewis(@Luminescer) April 26, 2012
Well that is what I did and here is my protocol:
- I have this easy mix stuff that dissolves pretty rapidly (see Experiments’ Products Page), and it requires 20g/L
- I want to make 100ml amounts for each water type (99% DDW and 99% D2O), so I need 2g of LB media.
- Add 2 g to the 100ml of water and stir.
- Suck up in a sterile syringe.
- Add 0.2 micron filter to syringe and pump into autoclaved glassware.
Presto!