The test process consists of a number of steps that occur on the io® Cartridge. These steps are performed under complete control of the io® or callisto™ Readers. The Reader uses pneumatic control to transport the specimen around the Cartridge. All reagents are located on the Cartridge as either contained liquid reagents, which are released under Reader control, or as dried reagents deposited into the appropriate area of the Cartridge. These are reconstituted as the specimen enters the area containing the deposited reagent. Following completion of the test process, the io® Cartridge is permanently sealed automatically by the Reader to prevent contamination due to the release of amplified material.
The io® and callisto™ systems utilise Atlas’ proprietary electrochemical detection technology which offers a highly sensitive detection with a wide dynamic range, which does not suffer many of the issues associated with optical detection technologies. Electrochemical detection does not require expensive, fragile optical sensors so can be delivered through a robust, low cost instrument that requires minimal maintenance and avoids complex optical calibration procedures. This is ideal for decentralised laboratories, POC and near-patient environments.
Atlas’ electrochemical detection method in conjunction with the design of the io® Cartridge enables high multiplexing. Multiplexing is achieved on the io® Cartridge by two mechanisms. The specimen is divided as it is transported through the Cartridge, so that detection can occur in 4 physically separated channels. The second mechanism uses different electrochemical labels, with discrete oxidation properties, for different targets, enabling chemistry-based multiplexing within each of these 4 channels. This approach rapidly amplifies the number of targets that can be detected from a single patient specimen.
The io® Cartridge has a high multiplex capacity (24) with an ongoing programme to continue to extend the catalogue of proprietary electrochemical labels, further expanding the multiplex capacity of the io® Cartridge system.