A novel protocol for generating high-affinity ssDNA aptamers by using alternating magnetic fields

Area of Science:

• Biotechnology
• Molecular Biology
• Biochemistry

Background:

• Aptamers generated via Systematic Evolution of Ligands by EXponential enrichment (SELEX) offer high specificity and affinity for molecular targets, enabling diagnostic and therapeutic applications.
• The conventional SELEX protocol is time-consuming and labor-intensive, typically requiring 5-15 rounds of selection.
• This study introduces a novel DNA aptamer screening method that bypasses the evolutionary selection process.

Purpose of the Study:

• To present a novel, rapid aptamer screening protocol.
• To demonstrate the efficacy of the Magnetic-Assisted Rapid Aptamer Selection (MARAS) protocol.
• To generate DNA aptamers against C-reactive protein (CRP) for potential cardiovascular disease diagnostics.

Main Methods:

• The Magnetic-Assisted Rapid Aptamer Selection (MARAS) protocol utilizes an external alternating magnetic field and target-bound magnetic nanoparticles.
• A competitive mechanism is employed to select DNA aptamers with varying affinities to the target protein.
• C-reactive protein, a cardiovascular disease indicator, was used as the model molecular target.

Main Results:

• The MARAS protocol successfully generated aptamers with dissociation constants in the nanomolar range.
• Aptamer performance was influenced by the frequency and field strength of the applied alternating magnetic field.
• The diagnostic utility of MARAS-generated aptamers was comparable to enzyme-linked immunosorbent assay (ELISA).

Conclusions:

• The MARAS protocol efficiently produces high-affinity and specific aptamers.
• This method significantly reduces screening time, completing in under an hour.
• The simplicity of MARAS suggests potential for easy automation in aptamer development.