Simultaneous Multisheet Multichannel Imaging Cytometry (SMMIC) System Powered by Adaptive Vertically-Aligned Multi-Sheet Array (VAMSA) PSF

Abstract

Volumetric interrogating of a large population of live specimens at high throughput is a challenging task that necessitates new technology. We propose vertical-aligned multi-sheet array (VAMSA) illumination PSF that enables interrogation of specimens flowing simultaneously through multiple microfluidic channels. The very geometry of PSF enables high quality cross-sectional imaging, and facilitates volumetric interrogation of specimens flowing through commercial microfluidic chip (consists of multiple flow-channels), which is a step towards large population screening. The SMMIC technique employs a unique combination of transmission grating, beam-expander and high NA objective system in a specific optical configuration to generate diffraction-limited illumination PSF (VAMSA-PSF). However, the detection is accomplished by a large field-of-view widefield 4f-system that consists of low NA objective lens, high performance fluorescence filters, and tube lens. Studies show high quality sectional images (resolution ∼ 2.5μm, and SBR ∼ 4.8dB) of HeLa cancerous cells at high flow throughput (flow-rate of, 2500 nl/min). A cell count of > 1k and volume reconstruction efficiency of ∼ 121 cells/min is noteworthy. In addition, SMMIC system demonstrate organelle-level resolution with a SBR comparable to that of confocal especially at low flow-rates. It is hoped that the proposed system may accelerates drug-treatment studies for a large population of live specimens to advance the evolving field of translational medicine and health-care.