The molecular biology platform ensures the following activities:

• design of expression systems including selection between different strains, expression vectors, selection markers, promoters, secretion signals, coding sequences, modes of codon optimization
• construction of the expression vectors
• transformation, clones screening and selection of the best producing clones
• production of Research Cell Banks

Two microbial expression systems are proposed for the expression of recombinant proteins and for the production of plasmid DNA: Escherichia coli and Pichia pastoris.

Up-to-date techniques are available for the design and the construction of expression vectors.

Pichia pastoris

This yeast has the ability to produce and secrete large quantities of protein in the cultivation medium, which facilitates the recovery of the biological material and significantly decreases the contamination with host cell proteins and facilitates the purification.

Escherichia coli

For protein expression, two types of construction (without or with signal peptide) using selected strains of E. coli (BL21, BL21/DE3) are proposed for three different expression strategies:

• cytoplasmic expression under soluble form
• cytoplasmic expression as inclusion bodies
• periplasmic expression

For plasmid DNA production, selected strains of E. coli are used (DH5α, DH10b).