Micro-Particle Tracking Velocimetry was used to measure the maximum extension and shear rates inside the cross slot and narrow microfluidic channels, respectively, for flow rates of 1 -20 µL/min. Cross-linked polystyrene tracer particles (Spherotech PPX-10-10) of diameter 1 µm were mixed with the samples corresponding to a mean inter-particle separation of 10 µm.