Microrheology of Biological Specimens

Read the full text PDFPDF Tools Share Abstract A great number of important biological phenomena that occur in living organisms demand energy transduction processes that critically depend on the viscoelastic properties of their constituent building blocks, such as cytoplasm, microtubules, and motor proteins. Accordingly, several techniques have been developed to characterize biological systems with complex mechanical properties at micron‐ and nano‐length scales; these are now part of an established field of study known as Microrheology. In this article, we provide an overview of the theoretical principles underpinning the most popular experimental techniques used in such fields, including video particle tracking, dynamic light scattering, diffusing wave spectroscopy, optical and magnetic tweezers, and atomic force microscopy. We report examples of both active and passive microrheology techniques and discuss their applications in the study of biological specimens, where the use of small volumes in controlled environments and the intrinsic heterogeneities of the samples can be critical conditions to both perform and interpret the experiments.