Flexural Rigidity of Microtubules Measured by Gold Stripe-Patterned Substrate

Microtubules (MTs) are highly dynamic tubular biopolymers, involving in many cellular processes such as intracellular transport, cellular structure maintenance, and cell division. All the processes require that MTs have adequate and adjustable flexural rigidity to cope with different functions. Despite the importance of MT mechanics, previously reported values of MTs' flexural rigidity vary significantly. Here we provide an explanation for such a longstanding discrepancy. Moreover, with the localization precision optimized to the nanometer-level, we find that the flexural rigidity of MTs is dependent on growth rate. Not only do our results show the importance of localization precision on flexural rigidity studies, but also highlight the significance of the MT growth rate.