AOC for Immuno-PCR (iPCR)

Oligonucleotide-based therapeutics is considered as the third major drug development platform, specifically focusing on regulating gene expression by targeting specific single-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). Antibody-oligonucleotide conjugates (AOCs) represent a promising therapy method by combining the cellular and tissue selectivity of antibodies with the sequence of a rationally-designed oligonucleotide payload. Besides the therapeutic application, AOCs are also useful biological detection tools used in different research areas such as the immuno-PCR (iPCR).

Creative Biolabs is pioneering AOCs development to treat a wide range of serious diseases and to be used as a detection tool. Our advanced and unique AOC platform to design, engineer, and develop effective AOCs that combine the high selectivity of monoclonal antibodies (mAbs) and high-quality oligonucleotide to meet various requirements. Now we offer AOCs design and development services for immuno-PCR (iPCR) analysis.

Fig.1 Structure of AOC. (Dovgan, 2017)

AOC Used for Immuno-PCR (iPCR) Application

AOCs can be used in immuno-PCR (iPCR) analysis as a novel detection method. In this technique, the target can be visualized directly using rolling circle amplification (RCA). Generally, the DNA primer is covalently attached to the antibody immunoassay probe and amplification is performed using circular DNA (precircled in situ by ligase). Amplification results in an AOC containing a long DNA molecule with hundreds of copies of the circular DNA sequence that can be readily visualized by fluorescence after hybridization with complementary fluorophore-labeled ONs. The RCA is often performed at 37 °C that does not need heat-cool cycles for amplification compared to the classic PCR protocol. Thus, this approach is of great advantage when isothermal conditions are required, such as in cell biology. In addition, further advancement of the iPCR contains the combination of PCR amplification with enzymatic ligation. This has led to the development of a powerful tool for the quantitative detection of proteins and their modification and interactions-proximity ligation assays.

Immuno-PCR is a powerful technique similar to enzyme-linked immunosorbent assay (ELISA), in which antibodies are used to detect and quantify specific antigens (analytes) from mixed samples. However, in immuno-PCR, the AOC binds to the immobilized analyte, and the attached DNA is amplified by RT-PCR. The application of AOCs in immuno-PCR provides a highly sensitive method for protein detection and quantification. It combines the specificity of antibody detection and the sensitivity of RT-PCR for nucleic acid detection, which is superior compared with standard ELISA. Immunoassay combined with RT-PCR has been a standard technique for more than 20 years.

Fig.2 Schematic representation of the different iPCR options (a-c) and the ELISA technique (d). (Dovgan, 2019)

Featured AOC Development Services at Creative Biolabs

With years of experience in antibody engineering, oligonucleotide preparation, bioconjugation, and targeted drug delivery, we have used our proprietary AOC development platform to develop a variety of AOCs projects. At present, we offer a full set of AOCs development services for immuno-PCR (iPCR) analysis. For more details and information, please feel free to contact us.

References

1. Dovgan, I. Antibody conjugates: integrated approach towards selective, stable and controllable bioconjugation (Doctoral dissertation, Strasbourg). 2017.
2. Dovgan, I.; et al. Antibody-oligonucleotide conjugates as therapeutic, imaging, and detection agents. Bioconjugate chemistry. 2019, 30(10): 2483-2501.

For Research Use Only. NOT FOR CLINICAL USE.