Sections of stainless steel microcapillaries of different inner diameters were mounted between a primary and a secondary chamber.
Figure 1a shows the device design, where the specimen is mounted between a flexure beam force sensor and a set of 1°-inclined thermal actuator beams.
Briefly, a single cardiomyocyte was mounted between a force transducer and piezoelectric motor.
Each plate was mounted between a knurled clamping area of 15 × 25 mm using a normal force of 1.5 kN.
For the convenience of observation with the nonlinear optical microscope, labeled cells were mounted between a cover glass and a slide with ~6 μm space in between.
For fluorescence, grids were mounted between a microscope slide and coverslip with 50% glycerol and imaged in a Deltavision RT microscope (Applied Precision, Issaquah WA) using an EMCCD camera.
The leaves were mounted between a custom slide and coverslip, submerged in 400 μL of distilled water and then sealed with petroleum jelly to prevent evaporation.
Skinned fibers were mounted between a force transducer (KG7A with bridge-amplifier DUBAM 7C, Scientific Instruments, Heidelberg) and a fixed clamp in skinning solution without Triton X-100 and pre-stretched by 10% of their initial length.
After the skinning procedure, one bundle was mounted between a fixed end and a force transducer (FT-03C model; Grass Instruments, Quincy, MA, USA) in a 0.8 ml chamber filled with the relaxing solution, adjusted to slack length, stretched by 20%, and subjected to an activation/relaxation cycle.
The strip was mounted between a piezoelectric motor (Physik Instrumente, Auburn, MA) and a strain gauge (SensorNor, Horten, Norway), lowered into a 30 μL droplet of relaxing solution (pCa 8.0) maintained at 37°C, and incrementally stretched to 2.2 μm sarcomere length measured by digital Fourier Transform (IonOptix Corp, Milton, MA).
