cDNA Display Mediated Immuno-PCR (cD-IPCR): A Novel PCR-based Antigen Detection Method

Area of Science:

• Biochemistry
• Molecular Biology
• Immunotechnology

Background:

• Immuno-PCR (IPCR) offers high sensitivity for antigen detection by linking antibodies to DNA reporters.
• Conjugating proteins like antibodies to DNA reporters presents significant technical challenges in IPCR development.
• Existing methods face difficulties in achieving efficient and stable antibody-DNA conjugation.

Purpose of the Study:

• To demonstrate the feasibility of IPCR using a novel cDNA display technology.
• To overcome the conjugation challenges in traditional immuno-PCR methods.
• To provide a robust platform for sensitive antigen detection.

Main Methods:

• Generated cDNA display molecules, which are 1:1 covalent complexes of a polypeptide and its encoding cDNA.
• Utilized in vitro transcription of antibody-encoding DNA to mRNA.
• Performed mRNA puromycin linker ligation, followed by in vitro translation and reverse-transcription.
• Applied the resulting cDNA display molecule directly for antigen detection and quantitative PCR (qPCR).

Main Results:

• Successfully established IPCR based on cDNA display at the single-molecule level.
• Demonstrated the ability to generate a covalent complex of antibody and its encoding cDNA.
• Validated the direct use of cDNA display molecules in antigen detection assays.

Conclusions:

• cDNA display provides a feasible and effective strategy to overcome antibody-DNA conjugation challenges in IPCR.
• This novel IPCR approach enables sensitive detection of various antigens in biological samples.
• The method is adaptable for detecting antigens using known single-domain antibodies (VHHs) or peptide aptamers.