A technique for simultaneous measurement of force and overlap between single muscle filaments of myosin and actin

In this study, we show a method for direct measurements of force and simultaneous visualization of isolated muscle filaments. Single actin filaments isolated from chicken skeletal muscle and single thick filaments isolated from Mussels were imaged using fluorescence and dark field microscopy, respectively. Force generated by the filaments was measured using micro-fabricated cantilevers. Force values were in the range observed previously with myosin filaments and molecules. The results suggest that the technique can be used to investigate many issues of interest and debate in the field of muscle biophysics.

Research highlights
► We have developed a new technique to perform experiments with single actin and thick filaments.
► We measured the forces generated by single actin and thick filaments while simultaneously measuring the degree of overlap between the filaments.
► The forces measured during myosin–actin interactions were comparable to previous studies using single myosin molecules.