What are ragged red fibers?
In some of the mitochondrial cytopathies, mitochondria become clumped beneath the skeletal muscle sarcolemmal membrane.
When the muscle biopsy specimen is prepared with modified Gomori’s trichrome stain and viewed by light microscopy, the clumps of mitochondria stain red and give the muscle fibers a ragged appearance—hence the term ragged-red fibers .
