902A: Laser Diode Sarcomere Length

902A – Alternative Method For Measuring SL In Fibers

CHALLENGE

In 2008 Dr. Todd Gillis was starting up his new lab at the University of Guelph and was interested in performing tests on both skeletal and permeabilized fibers.  Permeabilized fiber testing requires an initial measurement of sarcomere spacing to ensure the tissue is properly configured for testing, but thicker cardiac and diaphragm fibers can be a challenge to measure with a camera based method.

SOLUTION

Aurora Scientific designed a simple laser diode system that could be used as an alternative to our High Speed Video Sarcomere Length system for measure resting SL in thicker fibers.  The laser would mount on the side port of the microscope and could easily be swapped for a camera.  A removable target could be placed above the skinned fiber apparatus to measure resting SL, and then moved out of the way during the remainder of the experiment.  The equipment was made from sturdy but inexpensive materials to provide a true low cost alternative or add on piece to measure SL.

RESULTS

The custom made setup worked extremely well for thicker skinned fibers and consequently provided Dr. Gillis with an economical option for measuring SL in a number of large fibers. Our system helped validate the viability and configuration of the tissue for mechanical testing and limited the wasting of compromised tissue which was previously difficult to screen. Due to the success of this custom system, a similar version was built for use with our 801C intact muscle apparatus.  The setup has proven to work well for a variety of tissues and has spawned other research projects for laser based SL measurement at Aurora Scientific.