Label-free imaging flow cytometer for analyzing large cell populations by line-field quantitative phase microscopy with digital refocusing
Hidenao Yamada, Amane Hirotsu, Daisuke Yamashita, Osamu Yasuhiko, Toyohiko Yamauchi, Tsukasa Kayou, Hiroaki Suzuki, Shigetoshi Okazaki, Hirotoshi Kikuchi, Hiroya Takeuchi, Yukio Ueda
Abstract
We propose a line-field quantitative phase-imaging flow cytometer for analyzing large populations of label-free cells. Hydrodynamical focusing brings cells into the focus plane of an optical system while diluting the cell suspension, resulting in decreased throughput rate. To overcome the trade-off between throughput rate and in-focus imaging, our cytometer involves digitally extending the depth-of-focus on loosely hydrodynamically focusing cell suspensions. The cells outside the depth-of-focus range in the 70-µm diameter of the core flow were automatically digitally refocused after image acquisition. We verified that refocusing was successful with our cytometer through statistical analysis of image quality before and after digital refocusing.