Lactose in liquid RNAi


May I know if anyone has tried to use lactose instead of IPTG for liquid RNAi in 96 well plates? Since lactose supports bacterial growth better than IPTG, not sure if worms may suffer from hypoxia. Any suggestion would be very grateful.


It’s unlikely that anyone has used lactose. IPTG is a non-hydrolyzable molecular mimic of allolactose. Hence, levels should remain constant in an experiment. Lactose would be used by the bacteria as a carbon source and therefore would decline over time, leading to a weaker and more variable RNAi effect.

lactose does tend to give a weaker RNAi effect. in some cases that is good since it will give you the hypomorph phenotype and in others that is bad because you will miss something.
you can ameliorate the bacterial overgrowth by reducing available nitrogen (less tryptone and yeast extract - it’s going to be empirical, but approx 1/5 the normal amount is a good starting point).

Alright. Thank you very much!