Aptamer Screening Platform

Aptamer Screening Technology

Aptamers are single-stranded DNA or RNA sequences, which can fold into three-dimensional structures. Each sequence bears a randomized region of 20-60 nucleotides flanked by 5' and 3' fixed primer regions, and the random sequence block contained 1015 unique sequences. They are capable to combine with high affinity and specificity for their target molecules, similar to antibodies. At present, it has shown broad application potential in many fields such as therapeutic, disease diagnosis and biosensors, etc.

Alpha Lifetech has extensive experience in ligand screening technology, which is based on the Exponential Enrichment Ligand System Evolution (SELEX) technique for in vitro ligand selection. After years of development, Alpha Lifetech has established a comprehensive nucleic acid aptamer screening system, which can provide customers with high-quality nucleic acid aptamer (including RNA aptamers and DNA aptamers) screening services. Multiple screening targets such as proteins, peptides, amino acids, small molecule compounds, as well as various aptamer screening methods (such as magnetic bead SELEX, cell SELEX, capture SELEX, etc.) are available. The commonly used screening method is magnetic bead screening.

Technical process of Aptamer Selex Screening

The SELEX technique process for aptamer screening initiates from the build up of oligonucleotide libraries that consistes of DNA or RNA. Iterative cycles of selection and amplification achieved by incubating the oligonucleotide library with the target molecule, washing away unconjugated oligonucleotides, eluting the bound aptamers, amplifing the bound aptamers by PCR to generate a secondary library for the next round of screening. Repeat the steps of binding, partitioning, recovery, and re-amplification. Specific sequences enriched through this process emerge as dominant aptamers within the library.

Fig.1 SELEX Screening Technical Process

advantages of Nucleic acid aptamer

Advantages	Details
Direct	Avoiding the traditional process of animal experiments and selecting directly from in vitro libraries; selex screening for aptamers of target molecules that are non-immunogenic, low-immunogenic or even toxic.
Wide Range of Applications	The target molecules can be organic dyes, amino acids, proteins, antibiotics, peptides, vitamins, drugs, even cells, pathogens, viruses, tissues, etc.
Strong Affinity	Aptamers show high specificity and affinity for in vitro screening of target molecules.
Stability	Aptamers are small in size, easy to obtain, reproducible in synthesis, and their stability can be enhanced by chemical synthesis and modification. The aptamers are chemically stable, have a long shelf life and can be transported at room temperature.