An Experimental Study on the Improvement of Flow Cytometry Assay Stability by Ultrasound Aggregation-Assisted Sheath Fluid Focusing

Flow cytometers are widely used in clinical diagnosis, and the traditional sheath focusing method can reduce the detection stability due to high analysis speed. To improve this problem, an ultrasonic focusing-assisted sheath focusing method is introduced in the paper, a 5-channel optical system is designed, and multi-physics field simulation of the optical system and focusing effect is performed. The detection limit, linearity, and focusing stability of the device were verified experimentally using standard fluorescent microspheres as detection samples, and the results showed that: the detection limit of FITC (fluorescein isothiocyanate) of the device's device was 20.71 MESF, and the linear R2 was 0.99985; the detection limit of PE (phycoerythrin) was 3.14 MESF, and the linear R2 was 0.99953. In low speed In the low, medium and high analysis speeds, the stability of the detection results was better than that of the traditional focusing, which effectively improved the problem of affecting the stability of the detection due to the fast detection speed in the traditional sheath liquid focusing method.