We can clone what others can't

Large DNA fragments cloning and manipulating

Explogen offers cosmid libraries construction and sequencing at a highly competitive price. Typically, our genomic libraries have an average size of inserted DNA fragments around 41 kbp, that is sufficient for cloning of large chromosomal regions, for example natural products biosynthetic gene clusters. We are using in-house developed vectors (pEXG) that allows re-assembly of several DNA fragments into a single clone up to 120 kbp in size, that in most cases will cover even large polyketide synthase and non-ribosomal peptide synthase mega-clusters. The assembly vectors are designed to stably maintain large DNA fragments whilst simultaneously facilitating their purification in high yield.

As an alternative, the improved TAR (Transformation-associated recombination) cloning can be offered when a particular region of genome is desired. The use of our own vectors allows precise, direct cloning and stable maintenance of DNA fragments up to 90 kbp in size. Explogen TAR vectors are employing direct selection of clones with the insert of interest, significantly shortening time of cloning and increasing its efficiency. 

The pEXG vectors are designed in a modular way, allowing adapting them for different microorganisms and a variety of applications. 

Finally, Explogen is using diverse recombination tools to engineer large DNA fragments. We are able to perform a variety of manipulations, ranging from gene deletion and up to precise modification at the single nucleotide level of resolution. This includes:

  • gene deletion;
  • introduction of point mutation;
  • insertion of strong promoter, ribosome binding site (RBS) and terminator;
  • optimization of promoter and RBS by library screening.

We offer an individual approach for each project. The vectors system can be modified according to customer needs and project peculiarities (aim of the project – deletion, expression, sequencing; final destination host strain, integrative or replicative, etc).

Current Projects:
Cloning: 11 cosmid libraries constructed and sequenced.