Microfluidic cytometer based on dual photodiode detection for cell size and deformability analysis

Cellular mechanical properties play an important role in disease diagnosis. Distinguishing cells based on their mechanical properties provides a potential method for label-free diagnosis. In this work, a convenient and low-cost microfluidic cytometer was developed to study cell mechanical properties and cell size based on the change of transmission intensity, using a low-cost commercial laser as a light source and two photodiodes as detectors. The cells pass through a narrow microchannel with a width smaller than the cell dimension, integrated in a polydimethylsiloxane chip, below which the laser is focused. The transit time of individual cells is measured by the time difference detected by two photodiodes. This device was used to study the difference in cell mechanical properties between HL60 cells treated with and without Cytochalasin D. Furthermore, it was also applied to distinguish cells with different diameters, HL60 cells and red blood cells, by measuring the transmission intensity.