Double determinant immuno-polymerase chain reaction for detecting soluble intercellular adhesion molecule-1

Area of Science:

• Biotechnology
• Immunology
• Molecular Biology

Background:

• Detection of circulating antigens is crucial for disease diagnosis.
• Conventional methods like ELISA have limitations in sensitivity.
• There is a need for more sensitive antigen detection assays.

Purpose of the Study:

• To develop a highly sensitive method for antigen detection in sera.
• To evaluate the performance of the developed method compared to ELISA.
• To demonstrate the broad applicability of the developed method.

Main Methods:

• Development of double determinant immuno-polymerase chain reaction (DDI-PCR).
• Utilizing two monoclonal antibodies (MoAbs) to sandwich antigens.
• Immobilizing the first MoAb, followed by biotinylated second MoAb binding.
• Employing streptavidin to attach biotinylated DNA as a marker.
• Amplifying the DNA complex via PCR and analyzing products by Southern blot hybridization.

Main Results:

• DDI-PCR demonstrated a 10^3 times higher sensitivity in detection limit compared to ELISA for soluble intercellular adhesion molecule-1 (sICAM-1).
• Enhanced sensitivity was observed in both culture medium and sera from gastric cancer patients.
• The DDI-PCR system successfully detected antigens below the detection limit of traditional ELISA.

Conclusions:

• DDI-PCR is a highly sensitive and effective method for antigen detection in biological samples.
• The technique offers a significant improvement over conventional ELISA.
• DDI-PCR is versatile and applicable to various antigen-antibody systems using two MoAbs.