IQuant™ Analyser: A rapid quantitative immunoassay reader.

Abstract

Lateral flow immunoassays (LFIA) used in rapid quantitative point of care testing require an accurate, reliable and easy to operate instrument to read the LFIA kit and calculate the quantitative result value. We present iQuant® Analyser, an immunoassay reader designed for reading the Quanti® range of LFIA test kits for key markers such as HbA1C, Vitamin D, TSH etc. The instrument utilizes a laser based confocal optics system to capture the test and control lines from the LFIA kit, digitizes the fluorescent signal with high spatiotemporal resolution, computes necessary peak area ratios, applies calibration curves and declares the final result in an automated manner with minimal operator input. The instrument uses kit specific calibration information embedded on each LFIA test kit, to compute the final clinical parameter without using any external calibration chip. An intuitive icon based interface enables easy operation with minimal key presses, suited for point of care applications. The technology is designed in a modular manner to enable the instrument to perform tests on various parameters such as HbA1C, TSH, and Vitamin D etc without any hardware changes, using test-specific LFIA kits. The functional performance of the iQuant Analyser was verified over the range of expected area ratio values with standard reference cartridges that provided stable fluorescent lines. Repeatability of the instrument was found to be excellent with coefficient of variation (CoV) of area ratios found to be less than 1%. The inter-instrument reproducibility was also found to be good with CoV less than 4 %. Tests using blood samples with Quanti LFIA kits verified the accuracy of HbA1C results to be acceptable as per international standards with errors <; 4 %. The iQuant Analyser is a portable, easy to use rapid quantitative immunoassay reader best suited for point of care applications.