biopsy

https://doi.org/10.1351/goldbook.15515
Excision of a small piece of living tissue for microscopic or biochemical examination; usually performed to establish a diagnosis.
Source:
PAC, 2007, 79, 1153. (Glossary of terms used in toxicology, 2nd edition (IUPAC Recommendations 2007)) on page 1181 [Terms] [Paper]