(T1330-02-10) Novel Immunoassay Technology: Evaluating the PIXI Platform for Rapid Quantitation with Automation, Wide Dynamic Range, and Small Sample Volume Requirement

Purpose: The PIXI immunoassay platform revolutionizes immunoassay technology by utilizing electric current to drive antibodies or antigens toward their respective binding partners on a nanoporous matrix. This innovation addresses limitations in traditional plate-based immunoassays, such as slow diffusion and limited coating areas. The automated PIXI system eliminates incubation steps, reduces sample volume, and offers an impressive dynamic range spanning ~ 5 logarithmic orders.

Methods: We assessed PIXI's feasibility and performance in several immunoassay applications.

Results: First, we evaluated the PIXI's human IgG assay cartridge for rapid concentration determination during IgG purification from human sera. In less than 50 minutes, PIXI generated a robust standard curve (0.1 to 10^5 ng/mL IgG1; R2 = 0.993), demonstrating its efficiency. Secondly, we adapted PIXI for a murine model in a PK/PD study. We designed a customized assay using a biotinylated antibody to detect the target molecule in 10-fold diluted mouse sera, completing the assay in under an hour. PIXI's 2 μL per well sample volume minimized bleeding volume, enabling comprehensive longitudinal monitoring of the target molecule. Lastly, in our pursuit of developing an assay for human Interferon gamma (IFN), our methodology commenced with the meticulous biotinylation and fluorophore conjugation of multiple antibodies. A thorough evaluation involved testing six pairs of antibodies, coupled with a comparative analysis of two distinct buffers designed to facilitate the migration of IFN. This rigorous experimentation aimed at pinpointing the optimal antibody pair and buffer combination for the antigen. Remarkably, this work efficiently executed within a mere two days, underscoring the exceptional speed and efficacy inherent in the PIXI system's operation. This accelerated timeline not only speaks to the efficiency of our experimental approach but also emphasizes the agility afforded by the advanced capabilities of the PIXI system in expediting the development of crucial assays for biomedical research.

Conclusion: In conclusion, PIXI represents a groundbreaking immunoassay platform for rapid protein quantitation across diverse biological matrices. Its wide dynamic range eliminates the need for extensive sample dilutions, saving time and resources.