Overnight Express™ Instant LB Medium is a granulated autoinduction culture medium for high-level protein production in pET and other IPTG-inducible bacterial expression systems. Instant LB Medium is a combination of Overnight Express Autoinduction System 1 components (Cat. No. 71300) with Luria Bertani (LB) broth and is supplied in two formats. EasyPak is an aluminum foil pouch containing 45 g granulated medium, sufficient for 1 L culture. Just add the EasyPak contents to 1 L sterile water, supplement with 10 ml glycerol, and microwave for 2 min to dissolve. Overnight Express Instant LB Medium is also available in 1 kg bottles. Granulated medium ensures rapid, uniform dissolution in water, prevents clumping of the medium, and avoids inhalation of airborne powder.

Overnight Express™ autoinduction media are based on technology developed by F. William Studier at Brookhaven National Laboratory and enable regulated protein expression in E. coli, without monitoring the culture or adding IPTG during cell growth. The method uses media components that are metabolized differentially to promote growth to high cell density and automatically induce protein expression from lac promoters. As a result, these unique autoinduction media provide high-level protein production in pET and other IPTG-inducible bacterial expression systems. Cell mass and target protein yield are often increased several-fold compared to conventional protocols using induction with IPTG. Autoinduction media are extremely convenient for routine expression of proteins in multiple cultures and are ideal for high-throughput parallel analysis of protein expression, solubility, and purification from multiple expression clones.