Abstract
Rheological properties of isotropic fluids are frequently probed by microrheology, a set of techniques that uses the dynamics of micron scale particles to extract the viscoelastic properties either in a passive or in an active approach. For an anisotropic fluid like a nematic phase, these techniques are often applied but the mechanical properties of mesophases cannot be straightforwardly related to the dynamics of the beads. We have illustrated this by focusing on the microrheology of solutions of disodium cromoglycate, a lyotropic chromonic liquid crystal. We have probed this system with beads of several sizes with both passive and active methods and confronted our results to recent but apparently contradictory data present in the literature.