The advantages of gene design

Before planning your experiments consider the advantages of
 de novo gene designs which should be compared to classical
gene engineering and in vitro mutagenesis experiments by cost :

• Virtually unlimited options in designing gene sequences.
• Computer-designed genes are available as DNA hard-copies fast.
• Opens up new perspectives for in-vivo experimentation, e.g. by simultaneously mutating target proteins at different positions.
• Gene synthesis is a one-step procedure: design all desired mutations in one fell swoop, commission the gene assembly, and a few weeks later you will hold the desired gene in your hands - ready for further experimentation. Conventional mutagenesis requires repeated rounds of mutagenizing (via PCR) and cloning if multiple base changes are to be incorporated! Gene synthesis will save time and money if you intend to mutate multiple amino acids!
• 100 per cent sequence guarantee - we deliver quality controlled DNA sequences!
• Synthetically created gene variants are the fast track to elucidating structure-function relationship for proteins, e.g. in rational enzyme, vaccine or antibody design. Get your protein data faster and more conveniently. Avoid lengthy cloning and mutagenesis procedures! Gene synthesis provides all the required variants fast and efficiently.

Other features that easily can be modified/optimised are to :

• adapt GC content to the level observed in the host expression expression system
• optimise or minimise mRNA secondary structures to ensure highly efficient translation
• remove repeats or inverted repeats as well as homopolymer stretches
• generate or remove recognition motifs for restriction enzymes
  
• introduce, delete or alter protein modifications, e.g. glycosylation, phosphorylation etc. without difficulty
• modify the DNA sequence in various regions of the DNA: potential transcription initiation and termination sites, 3'-and 5'-UTRs, translation initiation site, etc.

Codon usage and sequence optimisation :

Organisms differ in their preference for using certain nucleotide triplets to code for individual amino acids. This usually reflects the frequency at which the cognate tRNAs occur and is the result of the evolutionary history of these organisms. The empirically observed frequencies are recorded in codon usage tables and are accessible from various sources, some on the Internet, such as the Codon Usage Database in Japan.

The problem with differential codon usage is that researchers sometimes run into trouble trying to express a gene cloned from one organism in a different organism, e.g. the human insulin gene in bacteria or yeast. Very often the result is low or no protein output.

Optimising codon usage overcomes these interorganismic limitations and has proven its value in increasing protein yield in such heterologous expression systems. What is done is to substitute individual codon triplets with the corresponding major codons in the host organism. This guarantees that only those tRNAs present at high frequencies are utilized while at the same time the protein's amino acid sequence remains unaltered.

We offer the development of projects or strategies to handle any RNA species. Specifics can be communicated on request.

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