A novel immunoassay system and bioseparation process based on thermal phase separating polymers

Area of Science:

• Biochemistry
• Polymer Science
• Analytical Chemistry

Background:

• Immunoassays are crucial for detecting biological molecules.
• Current heterogeneous immunoassays can be complex and time-consuming.
• There is a need for sensitive and efficient separation techniques in biological analysis.

Purpose of the Study:

• To develop a novel separation method for immunoassays using a polymer-antibody conjugate.
• To leverage the thermal precipitation properties of polyNIPAAm for analyte isolation.
• To enable homogeneous incubation with heterogeneous separation for improved immunoassay performance.

Main Methods:

• Conjugation of poly-N-isopropylacrylamide (polyNIPAAm) with a monoclonal antibody (MAb).
• Utilizing the temperature-dependent precipitation of polyNIPAAm (above 31°C) to separate immune complexes.
• Employing reversible redissolution of the polymer-immune complex by cooling.

Main Results:

• Demonstrated a novel separation method for immunoassays using polyNIPAAm-MAb conjugates.
• Achieved sensitive assaying of large-molecular-weight antigens comparable to non-isotopic heterogeneous immunoassays.
• Showcased the ability to concentrate signals and isolate analytes through reversible precipitation and redissolution.

Conclusions:

• The polyNIPAAm-MAb conjugate offers a versatile platform for homogeneous immunoassays with heterogeneous separation.
• This technique provides advantages in sensitivity, simplicity, and analyte isolation.
• The methodology is applicable to a broad range of separation processes beyond immunoassays, including product recovery and pollutant removal.