SELEX is a combinatorial chemistry technique for producing aptamers that specifically bind to a target ligand.
Since SELEX was first introduced in 1990 by Dr. Larry Gold at the University of Colorado, various aptamers have been developed that bind different targets.
The aptamers are selected through an iterative process consisting of binding the target with a highly diverse oligonucleotides library, washing unbound aptamer and amplification of survived oligonucleotides. Multiple rounds of SELEX enhance the enrichment of the oligonucleotides with high specificity for their targets. The best aptamer clones are selected after sequencing analysis and affinity assay with enriched oligonucleotides.
Next-generation aptamer platform technology for diagnostic and therapeutic applications through Modified Nucleoside SELEX and ViroSELEX
01Modified Nucleoside SELEX
Technology to discover high-quality aptamers from modified DNA library with improved binding affinity and diversity
Technology to improve the applicability of aptamer by displaying targets on the virus surface, mimicking the original environment
Sequencing-based aptamer selection technique analyzing sequence pattern and structural similarity
Modified nucleoside SELEX
- The higher success rate in the discovery of high-quality aptamers, compared to natural nucleic acid library-based 1st generation SELEX technology.
- Significantly enhanced binding affinity to targets by incorporation with a hydrophobic group
- The improved success rate in aptamer discovery with increasing the diversity in libraries
- Patented platform technology that enables the improvement of the specificity and applicability of aptamer
- Need for new SELEX technique due to technical difficulties in purifying membrane protein and limitation of cell SELEX
- ViroSELEX technology expresses the target proteins on the surface of the surrogate virus, providing environmental conditions similar to those of the original cell membrane.
- Competitive aptamer discovery technology for cell membrane protein-targeted therapeutics
Most cancer biomarkers are expressed in cell membrane.
→ It is important to discover cell membrane protein-targeted aptamers
Target proteins are expressed on the surrogate virus surface that is similar to natural cell membrane protein (PCT/KR2018/009662)
NGS sequence analysis: NGS and bioinformatics converge to build optimized aptamer discovery technology
- Possible to track pattern of the sequence increase/decrease during SELEX with NGS analysis
- Technology to increase the success rate in the discovery of aptamers with high specificity and binding affinity
Best sequence selection through aptamer sequence analysis in each round
→ Tracking of sequence increase/decrease in each round
→ Best sequence selection
Simultaneous analysis of pools of all rounds with barcode primer
→ Analyze all rounds of the pool simultaneously
→ Classification of the pool using barcode
Verification of diversity in libraries
→ Confirmation of sequence distribution uniformity in libraries
→ Improving the success rate of the SELEX process
Discovery of aptamer pair through NGS analysis
→ Group by sequence pattern
→ Selection of aptamer pairs by competition assay