Comparison of methods for measuring sarcomere length in beef semitendinosus muscle.

The objective of the study was to compare the precision of the laser method for measuring sarcomere length with the precision of two oil-immersion microscope methods. Eighteen semitendinosus muscles were assigned to one of three post-mortem treatments to provide a wide range in sarcomere length. Two 5·0cm sections were removed from the centre of each muscle. Each section was subdivided into six equal-size pieces and randomly allotted to each of three participating institutions. Analysis of variance revealed that sarcomere length measurement was not significantly affected by the method of measurement or by the technician. For 99% precision, the laser method required 34 measurements, whereas the two microscope methods required 45 and 66 measurements, respectively.