The 902A Laser Diode Sarcomere Length system is intended for manual measurement and setting of sarcomere length before or during an experiment. The product was designed for use with an 801C Small Intact Muscle Test Apparatus or an 802D Permeabilized Fiber Test Apparatus available from Aurora Scientific.
In operation, a laser beam is projected vertically upwards out of an unused objective port on an inverted microscope and through the tissue suspended in the apparatus tissue bath. The laser beam is diffracted by the sarcomeres in the tissue and this diffraction pattern is projected on the target. The laser beam separation is compared with lines printed on the target to determine and set the sarcomere length.
The system includes: SL target, target holder, laser diode, XY stage mount for the laser diode, laser diode on/off switch and laser diode power supply. The laser diode portion mounts to a C-mount adapter on the researcher’s inverted microscope.
- simple, manual measurement of sarcomere length
- compatible with all inverted microscopes (requires c-mount port adapter)
- SL target can be customized to researcher’s needs
902A – Alternative Method For Measuring SL In Fibers
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.
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.
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.