In glass, referring to a study in the laboratory usually involving isolated organ, tissue, cell, or biochemical systems.
See also: in vivo
Source:
PAC, 1993, 65, 2003. 'Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)' on page 2061 (https://doi.org/10.1351/pac199365092003)