In situ measurement of localization error in particle tracking microrheology

A method is presented to estimate the static error ε in a multiple particle tracking microrheology experiment. This in situ estimate of ε is measured under the same conditions of the material under test, and without any additional experiments. The correction of the mean-squared displacement by the in situ method is potentially more reliable than methods that rely on characterizing ε in a separate gel sample. With the true mean-squared displacements accessible at short lag times, experimental artifacts introduced by static error can be distinguished from true rheological properties, even in highly viscous (>10,000 mPa⋅s) samples.