Hi, I need your help finding the right and cheaper IPTG for RNAi screening experiments (clones are from Ahringer lab; need to induce T7 polymerase activity).
From Fisher Scientific’s website, I found the IPTG with catalog of BP175510 is like 10g for $44.44; but the one with FERR0392 is like: 5g for $149.6. Clearly, the first IPTG is much cheaper and will save money in the long run, but I don’t know if it is good for RNAi experiments. Also, I don’t understand why the prices are so different for the same IPTG. Can anyone give me some advice on picking the right IPTG? Or recommend the IPTG you are using in the lab to me?
Thank you very much for your help.

Hi Kim,

We buy IPTG from GoldBio. It is inexpensive and works fine.


A postdoc in my old lab often used just lactose instead of IPTG. It is significantly cheaper, although you have to add a higher concentration. The induction may not be as robust, but it’s worth a shot.

Thank you very much, Claire and Kevin!