In this article, the author describes the needed instrumentation and the methods to be followed for the observation and measurement of the birefringence of single and bundled microtubules and of their ordered arrays using a polarizing microscope. As instruments, the traditional polarizing microscope and the recently developed LC-PolScope are discussed. As methods, we describe qualitative and quantitative observations, including notes on specimen preparations, which optimize the sensitivity and accuracy of measuring specimen retardance.
