LBpowder - MetabolicEngineeringGroupCBMA/MetabolicEngineeringGroupCBMA.github.io GitHub Wiki

++LBpowder [protocol:] Revised 2012-02-06

A practical way of storing a LB stock in dry form (1).

Add the following components in a plastic bottle with a large cap.

for 5L media: 50g peptone OR tryptone
25g yeast extract
50g sodium chloride
(100g agar for solid media)
(2g Protocol for ampicillin stock solution powder OR 0.5g Kanamycin powder when appropriate or a liquid stock after microwaving)

For 500 ml liquid medium, take 12.5g (no agar!) or 22.5 g (with agar) of the mix and dissolve in tap water in a 1L Schott bottle.

Heat for 3-5 min at full power in a microwave oven with the cap shut tightly. If the media is not dissolved, repeat the heating step after removing the pressure.

Do not put more than about 500 mL in a 1L bottle, especially important if the media has agar.

This protocol works very well for LB-amp media, it seems that heating in microwave oven does not inactivate the antibiotic.

1. Iacoviello M. P., and S. A. Rubin. 2001. Sterile preparation of antibiotic- selective LB agar plates using a microwave oven. BioTechniques 30:963-965.