Pylon Technology
Immunoassays are ubiquitous in life science research, in clinical diagnostics and often a key element in clinical trials for biopharmaceuticals. Yet, current technology has not kept up with ever-changing needs.
In research, scientists continue to look for higher sensitivity and better precision and to achieve them with a lower sample volume. To answer complex questions and accelerate discovery, they need an immunoassay platform with built-in flexibility for rapid assay development and ready adaption of assay protocols for changing analytical requirements. Ease of operation is critical, with shortage of trained personnel. And cost efficiency is key.
In the clinical environment, the continuing push to improve healthcare efficiency is heightening the importance of near patient testing and faster time to results to support clinical decisions. Yet, it has proven challenging to deliver the level of assay performance that is more commonly associated with large central lab analyzers in the near patient environment with less infrastructure, lower operator skills and the need for faster time to results to fit into the clinical workflow.
Pylon changes everything
Pylon immunoassays incorporate advanced yet inherently simple concepts to deliver state-of-the-art performance without reliance on infrastructure often available only in the central laboratory. And by drawing upon proven fiber optics and semiconductor manufacturing knowhow, high-volume, low-cost implementation of the Pylon technology is achieved.
Pylon test strip
To achieve the multiple goals of advanced performance, ease of use, versatility in specimen requirements and scalability, Pylon immunoassay replaces conventional methodology with a Pylon test strip that contains everything needed to perform an immunoassay. The Pylon quartz-glass probe tip, coated with analyte-specific antibody, moves from well to well as it picks up the sample and goes through the assay steps of a classic sandwich assay. No fluidics are required, reducing instrument complexity and associated cost and maintenance.
Watch Pylon test strip in action.
Pylon cyclic amplification
Once the analyte in the sample binds with the antibody on the Pylon probe tip, the probe tip is dipped into the biotinylated antibody and then the Cy5-streptavidin-fluorescence (Cy5-SA) reagent. The probe tip is coated with a biocompatible polymer formulated to eliminate nonspecific binding. Signal amplification is achieved by embedding multiple copies of Cy5-SA in an inert polysaccharide matrix. The labeling cycle can be repeated to further enhance the signal.
Achieving high sensitivity
Pylon immunoassays combine the stability of fluorescence with polymer-enabled amplification to enhance signal while avoiding nonspecific binding and proximity quenching. The result is subpicogram per milliliter (pg/mL) detection of proteins in a short assay time of about 20 minutes.
Inert polysaccharide matrix enhances sensitivity without increasing nonspecific binding
Maintaining a low background is critical in achieving high sensitivity. As shown in the figure, the polysaccharide boosts the immune-specific signal without a significant increase in nonspecific binding.
Watch Pylon cyclic amplification in action.
Precision
In Pylon assays, the high affinity of streptavidin and biotin is a key to precision, as is the relatively narrow size distribution of the high molecular weight biopolymer matrix in which the fluorescence label is embedded. The use of Cy5-streptavidin-polysaccharide polymer as a common reagent for all Pylon assays ensures lot-to-lot as well as assay-to-assay consistency. And the inherently more stable, dry reagent format enhances performance. For example, for the Pylon PCT Assay, the intra-assay and inter-assay CV is 7–10% in the clinically relevant PCT concentration range.
Wide-range protocol
For analytes that have an inherently broad concentration range (e.g., β-HCG), the Pylon assay protocol includes two sequences for each sample: one optimized for high concentrations (using short binding times and low flow rates), and the other optimized for low-end detection (using a longer binding time and higher flow rate). This avoids having to dilute the sample following an out-of-range assay run, and to repeat the analysis, saving the cost and time associated with a rerun. The Pylon β-HCG Assay has a detection range of 1 to 300,000 IU/L.