NACALAI TESQUE, INC.

3rd generation of inducible LEXSY

(1) Colony screening "by eye" using a fluorescent reporter

The inducible protein expression platform LEXSY is based on integration of an expression cassette (containing a protein of interest) into a chromosomal locus of the host under control of a T4 RNA polymerase / TET repressor architecture.

Our new vector generation now allows convenient co-expression of the protein of interest with BleCherry conferring both, antibiotic resistance for selection as well as visible fluorescence under daylight as a direct read out for protein production.

Upon plating on solid media, expressing clones are identified "by eye" by their cherry color at daylight (Fig. 1), whereas flawed clones (gray color) can be excluded from further analysis.

Figure 1: Picture of induced LEXSY clones co-expressing the BleCherry reporter.

(2) Direct read out for protein production

The BleCherry fluorescence is an indicator for integrity of the system and its expression capabilities. Small samples (0.1 - 1 ml) are taken from the culture for measuring their cherry fluorescence. This allows post-inductional monitoring of expression and thereby optimization of the point of harvest (Fig. 2).

Figure 2: Cherry fluorescence of LEXSY cultures (#1-5) 48 and 72 h post induction. Samples of 1 ml were taken and fluorescence was determined (ex 590 nm / em 620 nm) allowing i) monitoring the time course of expression for individual cultures and ii) comparison of expression levels for various cultures [- (No Tetracycline), + (Tetracycline 10 mg/l)], H host control.

View the illustration of the 3rd generation of inducible LEXSY

( http://www.jenabioscience.com/images/b3e879b381/Illustration_ind_LEXSY_blecherry_EGE-1410__100625.pdf?utm_source=newsletter_jul10&utm_medium=E-Mail&utm_campaign=LEXSY%2BJul%2B2010 )

(3) Minimized vectors for easier cloning

In addition to the above, the new pLEXSY_I-3 vector generation has been reduced in size by about 1 kb compared to the previous vectors which allows easier cloning of large target genes (> 5 kbp) for expression.

(4) LEXSY products – all you need for cloning, expression, strain selection, and cultivation

LEXSY Expression Kits

Convenient all-in-one expression kits allowing constitutive or inducible, intracellular or secretory expression of target proteins

LEXSY Strains & Cultivation Kits

The LEXSY expression hosts, as strains or complete ready-to-grow cultivation kits.

LEXSY Media, Antibiotics, Additives

Everything for growth and maintenance of strains.

LEXSY Molecular Tools

Expression vectors and useful primers.

PCR and Cloning enzymes

All restriction enzymes for the pLEXSY-2 cloning sites, ligases, polymerases etc...

Need further information? Please check out the LEXSY section at the Jena Bioscience website!

( http://www.jenabioscience.com/cms/en/1/browse/1007/?utm_source=newsletter_jul10&utm_medium=E-Mail&utm_campaign=LEXSY%2BJul%2B2010 )