Ultraportable Flow Cytometer Based on an All-Glass Microfluidic Chip

Abstract

The flow cytometer has become a powerful and widely accepted measurement device in both biological studies and clinical diagnostics. The application of the flow cytometer in emerging point-of-care scenarios, such as instant detection in remote areas and emergency diagnosis, requires a significant reduction in physical dimension, cost, and power consumption. This requirement promotes studies to develop portable flow cytometers, mostly based on the utilization of polymer microfluidic chips. However, due to the relatively poor optical performance of polymer materials, existing microfluidic flow cytometers are incapable of accurate blood analysis, such as the four-part leukocyte differential count, which is necessary to monitor the immune system and to assess the risk of allergic inflammation or viral infection. To address this issue, an ultraportable flow cytometer based on an all-glass microfluidic chip (AG-UFCM) has been developed in this study. Compared with that of a typical commercial flow cytometer (BD FACSAria III), the volume of the AG-UFCM was reduced by 90 times (from 720 to 8 L). A two-step laser processing was employed to fabricate an all-glass microfluidic chip with a surface roughness of less than 1 nm, significantly improving the optical performance of on-chip micro-lens. The signal-tonoise ratio was enhanced by 3 dB, compared with that of polymer materials. For the first time, a four-part leukocyte differential count based on single fluorescence staining was realized using a miniaturized flow cytometer, laying a foundation for the point-of-care testing of miniaturized flow cytometers.

Opportunities in optical and electrical single-cell technologies to study microbial ecosystems

“…Aforementioned electrical techniques especially seem suitable for this purpose, because miniaturization of electronics is already advanced and they do not make use of consumables and sample preparation to the same extend that the optical techniques do. However, efforts are being made to miniaturize Raman spectroscopy and flow cytometry as well, with their main advantage being that their sensitivity is higher compared to the electrical techniques (Lapsley et al, 2013;Persichetti et al, 2017;Shrirao et al, 2018;Hao et al, 2020;Gökçe et al, 2021;Jin et al, 2021;Li et al, 2023;Park et al, 2023). Moreover, flow cytometers and Raman spectroscopes are becoming cheaper (Lam, 2004;Shapiro, 2004;Picot et al, 2012;Emmanuel et al, 2021), paving the way for cheap and portable microbial analysis.…”

Computational Hyperspectral Microflow Cytometry

“…Current microflow cytometers can be broadly divided into two categories: waveguide-integrated [17][18][19][20][21][22][23][24] and microscopic imaging-based. [1][2][3][4]25] Integrating optical waveguides into a microchip offers the significant advantage of precise light delivery and collection without requiring delicate optical alignment, thus enabling the design of compact optical circuits for flow cytometry.…”