Introduction: The fine aspiration microbiopsy is a relatively new biopsy technique, which allows muscle physiologists to sample skeletal muscle less invasively. However, the small sample size obtained is often deemed insufficient for certain analyses. The aim of the current study was to develop procedures for muscle fiber morphology and immunohistological analysis from a microbiopsy technique.
Methods: Microbiopsies of the vastus lateralis were taken with a 14-gauge microbiopsy needle from four healthy men on two separate occasions. The tissue was oriented in a cryomold, embedded in Tissue-Tek® then frozen in liquid nitrogen cooled isopentane. The muscle sections were stained with hematoxylin and eosin, laminin, MHCI, MHCIIa, and Pax7 for fiber number, mean fiber area, muscle fiber typing, and satellite cell observation.
Results: The mean ± SD (range) microbiopsy sample weight was 18.3 ± 2.9 mg (14–22 mg). The mean fiber number within the microbiopsy specimens was 150.4 ± 120.6 (64–366). All viable fibers were measured in each sample, and the mean fiber area was 4385.1 ± 1265.8 μm2 (977.0–10,132.93 μm2). There was no significant time difference (P = 0.69) in mean fiber area.
Discussion: Results suggest the potential use of a “minimally invasive” muscle biopsy technique for immunohistological and morphological analysis. This could provide clinicians and investigators additional data in future research. Further investigations are needed to determine the usefulness and potential limiting factors of this technique.
1Institute of Exercise Physiology and Wellness, University of Central Florida, Orlando, FL; 2College of Medicine, University of Central Florida, Orlando FL; and 3Quest Diagnostics, Madison, NJ
Address for correspondence: Jay R. Hoffman, Ph.D., College of Education and Human Performance, Institute of Exercise Physiology and Wellness, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816; E-mail: Jay.Hoffman@ucf.edu.
Submitted for publication June 2015.
Accepted for publication September 2015.