Development and application of a system for very long-time microrheology experiments

Abstract

In this work, a new tool for passive microrheology is presented. Passive microrheology is currently limited in speed and measurement duration by the used video camera system. Normal cameras are limited in speed while high-speed cameras are limited in the recording time. To overcome these limitations, a complementary metal-oxide-semiconductor (CMOS) image sensor was coupled with a field programmable gate array (FPGA) to directly compute the position of the particles in the image and only save the position data instead of the complete image to reduce the data rate significantly, allowing basically infinite recording times with very high speed. In this work, the algorithms and optimizations for real-time particle tracking and the implementation into an FPGA is demonstrated. Then the system is validated for precision and usability and tested with passive microrheology measurements of polystyrene beads in NIH/3T3 mouse fibroblasts partially treated with blebbistatin to demonstrate the function and versatility of the device.