Closed needle liver biopsy for assessment of monooxygenase activity in rhesus monkeys (Macaca mulatta).

Closed needle liver biopsy routinely provides 60-100 mg tissue from rhesus monkeys (Macaca mulatta). No mortality or morbidity was observed in over 400 needle biopsies during a two-year period in which some monkeys were biopsied over 30 times. Biopsy tissue was used as enzyme source in low-volume in vitro systems for measurement of hepatic monooxygenase activity.