i-scope: a compact automated fluorescence microscope for cell counting applications in low resource settings.

Abstract

Fluorescence microscopy has widespread applications across biological sciences. It has been routinely used for cell counting, which provides a preliminary diagnostic test for many infectious diseases. Conventional fluorescence microscopes are bulky, expensive, time-intensive and laborious. They often require trained operators to acquire and analyze data. We report a compact automated digital fluorescence microscopy system,i-scope, for cell counting applications. Thei-scopeemploys a total internal reflection fluorescence (TIRF) mode of sample illumination, along with a brightfield mode. It has a magnification of 30X, an optical resolution of ∼0.2μm/pixel and offers sample scanning over 20 mm × 20 mm. A custom-written program enables automated image acquisition and analysis, thereby enhancing ease of operation. It has a compact form-factor and has been developed into a standalone system with a processing unit, screen, and other accessories to offer a portable and economic point-of-care diagnostic solution in low-resource settings. We analysed the performance of the i-scopefor milk somatic cell enumeration and benchmarked it against that of a conventional fluorescence microscope.