Human muscle biopsies are often required to study or diagnose diseases. However, traditional approaches are challenging due to limited sample size, quality, or participant discomfort. Fine-gauge needle biopsies (≥ 14-gauge), present an alternative but may yield insufficient tissue for comprehensive analysis. Ultrasound guidance, coupled with vacuum-assisted, single needle-insertion multiple sampling addresses these challenges. In 19 healthy participants (mean age: 30.1 ± 10 years, 42% male), 2-3 samples were collected from a single needle insertion into the vastus lateralis (VL) and tibialis anterior (TA). Summed VL and TA sample masses averaged 148 ± 38 mg and 166 ± 64 mg, with dimensions of 15.83 ± 8 × 2.9 ± 0.6mm2 (VL) and 15.07 ± 7 × 3.1 ± 0.9mm2 (TA). VL had a mean fiber cross-sectional area of 4,347 ± 1,931µm2, with 221 ± 86 fibers quantified. Samples were of sufficient size and quality for thorough analyses from a single biopsy procedure, including mitochondrial respirometry, RT-PCR, collagen content, and biomechanical function. Fibers produced typical isometric stress values of 187 kPa with a passive modulus of 239 kPa (peak) and 79 kPa (stress-relaxed). The procedure was well tolerated, with an average immediate pain rating of 1.5 ± 1 (range:0-4, scale: 0-10) and 24-hour follow-up rating of 1.7 ± 1 (range:0-4). This report describes an approach that yields high-quality muscle samples suitable for histological and biochemical analyses while minimizing discomfort.
Barber et al. (2026) studied this question.