text: <unk>  (Latin: (with) in the glass) refers to the technique of performing a given experiment in a test tube, or, generally, in a controlled environment outside a living organism.<unk>  fertilization is a well-known example of this. Many experiments in cellular biology are conducted outside of organisms or cells; because the test conditions may not correspond to the conditions inside of the organism, this may result in inaccurate results. Consequently, such experimental results are often annotated with<unk> , in contradistinction with in vivo .
option_0: In vitro
option_1: Cell culture
option_2: Virus classification
option_3: In silico
option_4: Primary isolate
option_5: Fermentation 
option_6: Electron
option_7: Serotype