A common method for analyzing microtubule motor activity is to
attach them to a glass coverslip (the tails stick very well to
glass) and then incubate with microtubules, which will settle on
them and then “glide” across the surface of the coverslip as the
heads of the motors propel them. This is easily observable in the
light microscope. In an assay such as this, how can one determine
the directionality of the movement of the microtubules (plus- or
minus-ended)? Assume that you do not know if the motor is a plus-
or minus-end motor prior to the experiment.
Other than directionality, could you determine other properties
of the motor in your setup from the question above?