1) We've been using the beta-lactose from Sigma (L-8773). 20%
solution, made up in water, filter sterilized, then stored at -20.
2) We haven't tried MYOB or standard NGM.
3) We have done a few experiments with M9 minimal medium (recipe
below), which should be better for induction because it has very
little glucose. The RNAi effect does seem to be more potent than
with NGM-lite, so this would be my first choice for maximal induction.
4) 0.2% lactose seems to work better than 1% lactose.
M9 (per liter):
Na2HPO4 6 grams
KH2PO4 3 grams
NaCl 0.5 grams
NH4Cl 1 gram
Casamino acids 5 grams
Agar 20 grams
Autoclave, then add CaCl2, cholesterol, Amp, Tet and lactose.