Non-equilibrium distribution of kinesin-streptavidin complexes revealed by Mass Photometry.

Kinesin-streptavidin complexes are widely used in microtubule-based active-matter studies. The stoichiometry of the complexes, formed under non-equilibrium conditions, is empirically tuned but the distribution has not been experimentally determined. Here we directly measure the distribution of kinesin-streptavidin complexes via mass photometry. We identify conditions that maximize the desired complex stoichiometry.