Skeletal muscle tissue sample (IMAGE) Purdue University Caption Stained, cross-sectional sample of skeletal muscle tissue. Muscle cells (myofibers) of differing contractile type, such as fast vs. slow twitch fibers, are distinguished via their resulting staining color. (Credit: Image provided by James Markworth/Purdue University) Credit Image provided by James Markworth/Purdue University Usage Restrictions News organizations may use this image in reports about the work of Purdue University's James Markworth and his collaborators. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.