Aptamer
Aptamers are composed of nucleic acids, generally single-stranded DNA or RNA (ssDNA or ssRNA) molecules. After special design and screening, they can be folded into a 3D stereoscopic structure with binding force. Like antibodies, they have antigen recognition ability and can selectively bind to specific targets. Therefore, they are also called "chemical antibodies". The structure of aptamers is smaller than that of antibodies. Nucleic acids have helical properties and are easy to form ring structures. They have high structural variability. The binding method can depend on the structure, hydrophilicity, and base embedding. Therefore, they are not limited by immunogenic targets. The application range is wider than that of antibodies. They can accurately identify targets such as ions, small molecules, proteins, cells, tissues, and microorganisms. The unique aptamers developed by Xinyuan using the exclusive Genimer™ screening technology platform are called Genimer™ .
Genimer™ Features
Composed of nucleic acids and with a small structure: Nucleic acids can be stably stored in acidic, alkaline or high temperature environments. They are approximately 10-15 kDa in size, 10 times smaller than the 150 kDa size of typical antibodies. They have small molecule binding potential and can cross the blood-brain barrier.
Wide range of applications: Geimers are not limited by immunogenic targets, so their application range is wider than that of antibodies.
Short development time: Geimers are developed faster than antibodies.
The manufacturing process is cheap, fast and stable: Nucleic acid aptamers are synthesized chemically, without the need for living cell production and complicated purification processes. Therefore, the process cost is low and can be produced quickly. It can also ensure that the specificity and affinity are not affected by the batch-to-batch differences in living production, and the stability is high.
Traditional aptamer SELEX technology
Aptamers are usually screened from large single-stranded DNA or RNA aptamer libraries (oligonucleotide libraries) through SELEX (Sequential Evolution of Ligands by Exponential Enrichment) technology to identify aptamers with specific target affinity. The aptamer library of traditional SELEX is usually composed of 30 to 50 random bases. Through screening, aptamers without binding ability are removed and aptamers with target binding ability are expanded. Multiple rounds of screening cycles (usually more than 10 rounds) are performed using target and non-target (similar substances or environmental factors) to obtain aptamers with specificity and affinity.
Genimer™ Screening Technology Platform
CoreGene developed a unique Genimer™ screening technology platform that integrates aptamer library prediction software, SELEX, NGS, molecular simulation technology and AI system. The platform can quickly generate high-affinity and high-specificity aptamers. Compared with traditional aptamer technology, it has the advantages of short development time, high throughput and improved affinity, supports customized development, and provides innovative solutions for biological detection.
Advantages of choosing Genimer™ Custom Development Services
Improve the formation rate of affinity structures: The fixed backbone and shorter sequence of the structured sequence help to form functional ring structures more efficiently, which is very important for the specificity, affinity, stability and anti-degradation of the aptamer.
Shorten screening time: The screening library has been optimized to reduce complexity and improve affinity. It only takes 5-10 rounds (about 7-14 days) to complete the screening, which is more than 2 times faster than traditional screening.
High-throughput sequence analysis avoids missing candidate aptamers: The screening results are sequenced using NGS for high-throughput sequencing, and high-frequency candidate aptamer sequences are found through bioinformatics analysis methods to avoid bias or omissions caused by traditional random selection sequencing methods.
Improve validation efficiency: Candidate aptamers are analyzed using structural simulation and molecular docking simulation to quickly select candidate aptamers with affinity, reduce the number of candidate aptamers, and reduce the time and cost of functional validation.
Improve aptamer affinity: Analyze aptamer sequences with affinity, optimize the sequences through affinity maturation technology, and develop aptamers with high stability and high affinity through simulation software and functional verification.
Advantages of Genimer™ over Antibodies
PSA Aptamer - BLI (Bio-Layer Interferometry) Test
Biolayer Interferometry (BLI) for Biomolecular Interaction Analysis
Biolayer Interferometry (BLI) is a label-free optical analytical technique used to measure biomolecular interactions. It works by detecting interference patterns of white light reflected from two surfaces: the interface between immobilized molecules on the biosensor tip and the external buffer, and an internal reference layer interface.
When white light illuminates the biosensor, reflections occur from both surfaces. Due to phase differences between the reflected light at various wavelengths, different interference intensity values are observed. When molecules bind to the immobilized molecules on the biosensor tip, the increased thickness of the biomolecular layer leads to an increase in reflection distance. This change in reflection distance alters the phase of the reflected light, causing a shift in the interference intensity. The instrument can detect this interference intensity shift (Δλ) in real-time. Importantly, changes in the refractive index of unbound molecules or the surrounding medium do not affect the interference pattern. BLI can be used for accurate and rapid determination of aptamer kinetic constants.
Our Research Using BLI with PSA Aptamers
We immobilized PSA aptamers onto BLI biosensors to evaluate their binding affinity with PSA protein, their binding characteristics at different PSA protein concentrations, and the repeatability of their binding to PSA protein. Our results confirmed that the aptamers exhibit high specificity and affinity, and are reusable.
PSA Aptamer- Semiconductor Biomedical Chip Testing
The core technology used in semiconductor biomedical chip systems is "silicon nanowire field-effect transistor" (SiNW-FET), which is a semiconductor technology application that uses current signal detection and has the characteristics of fast, instant, and high sensitivity. This technology combines cross-domain technologies such as semiconductor biomedical detection chips, heterogeneous packaging, chemical surface treatment, biochemical molecular processing, microfluidic automatic control systems, micro-signal scanning measurement circuits, data processing programs, and platform mechanism design and production with electrical principles. Using Bio-FET technology as the core, a highly sensitive automated detection platform is established with a detection time of 5-30 minutes. The targets include nucleic acids, proteins or chemicals in the environment. The high-sensitivity detection limit is 10^-15 M for nucleic acids and 10^-12 g/ml for proteins.
We fixed the PSA aptamer onto a semiconductor biomedical chip and tested the biomedical chip detection signal of different concentrations of PSA protein. We were able to successfully detect 100 pM of the target, and the detection result was positively correlated with the concentration, proving that the aptamer combined with the biomedical chip detection platform has high sensitivity and stability.
Rapid screening test piece test
For small molecule targets, such as tetracycline, due to its relatively small structure, the molecular surface cannot provide more than two areas for molecular probes such as antibodies or aptamers to identify and bind, so competitive detection must be used. The competitive method is to first fix the target of a fixed concentration to the detection area, and fix the probe to colloidal gold. When the sample does not contain the target, the probe will bind and react with the target. When the sample contains the target, the probe will first react with the target in the sample, competing for the amount of probe that will bind to the detection area. This method is used to detect small molecule targets.
We used the ability of aptamers to recognize small molecules and combined them with rapid screening test strips. Through competitive methods, we were able to successfully perform tetracycline detection, proving the feasibility of applying the method to food safety testing.
Through continuous innovation and research, we are committed to pushing the boundaries of biomedicine and providing a solid scientific and technological foundation for future medical challenges.
Core Technology
Aptamers were discovered in 1989, and in 1992, it was discovered that the SELEX (systematic evolution of ligands by exponential enrichment) technology could screen aptamers. However, the aptamer screening technology was protected by patents until 2010, when the key patents expired and the cost of nucleic acid synthesis dropped significantly after 2015. Aptamer research has grown explosively, with thousands of papers published in five years. These studies have shown that aptamers have unique properties and wide applicability.