Changes in diffraction patterns with length in single muscle fibres at rest.

The addition of a simple X--Y sampling circuit to a closed circuit television system (CCTV) permits measurements of a narrow profile of the laser diffraction patterns from single frog muscle fibres at rest. Results confirm that maximum intensity occurs at 2.95-3.00 micron, but a positive linear relationship between the dispersions of sarcomeres and sarcomere lengths from 2.7--3.8 micron is obtained in four isolated single fibres.