Magnetic Cell Centrifuge Platform Performance Study with Different Microsieve Pore Geometries

The detection and analysis of circulating tumor cells (CTCs) plays a crucial role in clinical practice. However, the heterogeneity and rarity of CTCs make their capture and separation from peripheral blood very difficult while maintaining their structural integrity and viability. We previously demonstrated the effectiveness of the Magnetic Cell Centrifuge Platform (MCCP), which combined the magnetic-labeling cell separation mechanism with the size-based method. In this paper, a comparison of the effectiveness of different microsieve pore geometries toward MCCP is demonstrated to improve the yield of the target cell capture. Firstly, models of a trapped cell with rectangular and circular pore geometries are presented to compare the contact force using finite element numerical simulations. The device performance is then evaluated with both constant pressure and constant flow rate experimental conditions. In addition, the efficient isolation of magnetically labeled Hela cells with red fluorescent proteins (target cells) from Hela cells with green fluorescent protein (background cells) is validated. The experimental results show that the circular sieves yield 97% purity of the target cells from the sample with a throughput of up to 2 μL/s and 66-fold sample enrichment. This finding will pave the way for the design of a higher efficient MCCP systems.status: publishe

Fast Tunable Biological Fluorescence Detection Device with Integrable Liquid Crystal Filter

Detecting a variety of biological samples accurately and swiftly in an integrated way is of great practical significance. Currently, biofluorescent spectrum detection still largely relies on microscopic spectrometers. In this study, we propose an integrable method to detect biofluorescent spectrums with designed liquid crystal tunable filter (LCTF), in order to identify typical biological samples such as cells and bacteria. Hela cells labeled with red and green fluorescent proteins and Pseudomonas with fluorescence wavelengths of 610 nm, 509 nm and 450 nm, respectively, are inspected. High-resolution (6 μm) biofluorescent results have been achieved, together with clear images of the Hela cell clusters and the Pseudomonas bacteria colonies. Biofluorescence signals can be detected at a high transmittance (above 80%), and the response time of the device can reach 20 ms or below. The proposed method has the potential to be integrated into a microfluidic system to detect and identify the biofluorescent signals as a high throughput, low-cost option, for both high resolution and large field observation applications