Muscle fibers are divided into three types: slow twitch (type I) or red fibers due to the large number of mitochondria they possess, fast twitch (type IIb) or white fibers and intermediate (type IIa).

Mammalian skeletal muscle mainly consists of four different types of muscle fibers, which are composed of different myosin ...

To overcome this issue, Ng and colleagues decided to examine the fiber distribution by using mass spectrometry imaging (MSI), which can capture high resolution images of intact frozen muscle sections.