The improvement of molecular diagnostic methods (PCR, DNA probes, FISH) and successful completion of the "Human Genome" project by high-performance sequencing gave a significant impetus to the use of synthetic oligonucleotides in laboratory and medical practice. Today, synthetic oligonucleotides are used not only for scientific purposes (primers for PCR and sequencing, genes constructing and vectors for genome modification), but also have independent practical significance as therapeutics (antisense oligo, siRNA, ribozymes, aptamers), DNA vaccines constructing, means for early diagnostics or susceptibility to hereditary diseases, as well as for personal identification. As of March 2017, approximately 130 clinical trials associated with antisense oligos were being conducted. 6 oligonucleotide drugs was approved by FDA as therapeutics (Molecular Therapy, 2017, 25 (5) 1069-1075).
Therapeutic oligonucleotides act by different mechanisms: reduce expression of undesirable genes or mRNA (antisense oligos, siRNA, atagomirs), bind and inhibit toxic proteins (aptamers), cleave foreign RNA (gapmers, ribozimes). But common requirement for them is resistant to body enzyme systems, which is impossible without their chemical modification (phosphorothioates, morpholino, PNA, LNA and other derivatives).
Currently, the most effective method for producing natural and modified oligonucleotides is 4-step phosphoramidite method on porous glass (CPG) that is implemented in automatic synthesizers K&A Laborgeraete (Germany). Due to complete isolation of highly active reagents from atmospheric oxygen, K&A synthesizers are capable of producing very long oligomers (more than 200 bases) with any imaginable modifications in amounts from a few micrograms (nMol) to hundreds of milligrams (mkMol). Syntheses can be performed in parallel on a 6, 8, 16 or 32 column instrument.
The stepwise photometric monitoring amounts of cleaved trityl for each column allows estimate synthesis quality in real time. The extremely short time to attach one base (3-6 minutes) makes it possible to produce dozens of oligonucleotides during the working day.
Together with oligosynthesizers K&A offers cleavage oven to remove ready oligos from CPG and eight-column purifiers for 20 min purification of these oligos to 90% purity - complete technology for self preparation of primers, probes, labeled and modified oligos. As distributor of K&A we are fully ready to transfer this knowledge to our customers. On customers request partial reconfiguration of oligosynthesizers can be made on factory.
