Aptamers as ligands in affinity probe capillary electrophoresis

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Biology

Background:

• Immunoglobulin E (IgE) is a key mediator in allergic reactions.
• Accurate quantification of IgE is crucial for diagnosing and monitoring allergic diseases.
• Existing methods for IgE detection can be time-consuming or lack specificity.

Purpose of the Study:

• To develop a novel, rapid, and selective method for IgE determination.
• To utilize a DNA aptamer as a fluorescent probe for IgE detection.
• To validate the method's performance using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF).

Main Methods:

• A DNA aptamer specific to IgE was synthesized and labeled with a fluorophore.
• Capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) was employed for separation and detection.
• The assay involved monitoring the fluorescence signal of free and IgE-bound aptamer.

Main Results:

• CE-LIF separations were completed in under 60 seconds.
• A linear dynamic range of 10^5 and a detection limit of 46 pM for IgE were achieved.
• The assay demonstrated high selectivity, unaffected by IgG, and IgE did not bind to other DNA sequences.
• IgE was successfully quantified in human serum samples.

Conclusions:

• Fluorescently labeled DNA aptamers coupled with CE-LIF provide a sensitive and selective platform for IgE detection.
• This method offers a rapid alternative for IgE quantification in clinical diagnostics.
• The aptamer-based CE-LIF assay can be adapted for detecting other biomarkers, such as thrombin.