IPTG

Isopropyl-beta-D-thiogalactopyranoside

Induces transcription from promoters regulated by LacI repressor.

Molecular weight is 238.31 g/mol. The chemical formula is here.

1. Dissolve 1g in 4196 μL deionized water to make 1M solution.
2. Filter sterilize with syringe and 0.22μm filter

Alternatively

1. Dissolve 238 mg IPTG (sigma I-6758) in 10 ml DW for (100mM stock)
2. store in 1 ml aliquotes at -20°C

Generally a 1mM solution is an effective amount to induce the pLac promoter region. It should be noted that this may vary over cell strains. For example:

• lacIq: cell strains which overproduce LacI repressor (ie. E. coli cell strain type D1210, aka. BBa_V1003)

For including IPTG in LB agar plates, a typical amount people recommend is 0.1-0.5mM IPTG.