A muscle biopsy is a minor surgical procedure in which a portion of muscle tissue is collected for closer examination. This test can reveal the presence of certain diseases related to connective tissue and blood vessels, to identify an infection or muscular disorder, or to evaluate certain metabolic muscle defects. It can also help your doctor determine whether a particular disorder is related to the muscle tissue itself (myopathies) or may be tied to the nerves that connect the muscles (neuropathies). This is an outpatient procedure that can be done in the doctor’s office with just a local numbing agent and the patient fully awake the entire time. The tissue sample may be collected via a needle that is inserted into the muscle (called a needle biopsy), via a small incision into the muscle (called an open biopsy), or using a suctioning device (called a vacuum-assisted biopsy). Biopsies may be assisted with CT scans and other imaging to ensure that the tissue sample is taken from exactly the right location.