A fast and ultrasensitive ELISA based on rolling circle amplification.

Area of Science:

• Biochemistry
• Molecular Biology
• Assay Development

Background:

• Enzyme-linked immunosorbent assay (ELISA) is crucial for disease diagnosis and biomarker discovery.
• Existing ELISA methods face limitations such as poor repeatability, high costs, complex equipment needs, and lengthy reaction times.

Purpose of the Study:

• To develop a fast and ultrasensitive ELISA (RELISA) by integrating rolling circle amplification (RCA) and enzymatic signal amplification.
• To overcome the limitations of traditional ELISA technologies for improved early disease diagnosis.

Main Methods:

• Incorporated a rolling circle amplification (RCA) step into the traditional ELISA protocol.
• Utilized the amplified single-stranded DNA (ssDNA) from RCA to enrich horseradish peroxidase (HRP) conjugate detection probes.
• Employed HRP to catalyze the TMB-H2O2 reaction for enhanced colorimetric signal generation.

Main Results:

• The developed RELISA achieved a limit of detection of 2.82 pg mL-1 for the CEACAM-7 biomarker.
• Demonstrated a sensitivity approximately 50 times higher than traditional ELISA methods.
• The RCA step, crucial for amplification, was completed within 10 minutes.

Conclusions:

• The RELISA provides a powerful tool for ultrasensitive and rapid biomarker detection.
• This method holds significant potential for early diagnosis of major diseases.
• RELISA addresses key limitations of conventional ELISA, offering improved performance and efficiency.