in vitro

American  

[in vee-troh] / ɪn ˈvi troʊ /

adverb

1. (of a biological process) made to occur in a laboratory vessel or other controlled experimental environment rather than within a living organism or natural setting.

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in vitro British  

/ ɪn ˈviːtrəʊ /

adverb

1. (of biological processes or reactions) made to occur outside the living organism in an artificial environment, such as a culture medium

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in vitro Scientific  

/ ĭnvē′trō /

1. In an artificial environment, such as a test tube.

2. Compare in vivo

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in vitro Cultural  

1. In the laboratory; literally, “in glass” (laboratory experiments are often carried out in glass containers). In vitro conditions are distinguished from conditions that actually apply in nature. (Compare in vivo.)

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Discover More

In vitro appears in the expression in vitro fertilization , a way of producing human embryos in a laboratory.

Etymology

Origin of in vitro

First recorded in 1890–95; from Latin in vitrō, literally, “in glass”

Compare meaning

How does in-vitro compare to similar and commonly confused words? Explore the most common comparisons:

• in vivo vs. in vitro

Example Sentences

"These clones were then evaluated in vitro and in a mouse model to observe their ability to migrate through a real biological filter and generate metastases," adds Arwen Conod.

From Science Daily • Mar. 21, 2026

Yet in January, she tried again, five years after her first attempt at in vitro fertilization.

From The Wall Street Journal • Nov. 14, 2025

"It was an in vitro and in vivo project, both providing the same outcome," Norris says.

From Science Daily • Oct. 22, 2025

This technology is part of a growing field aiming to make sperm and eggs outside of the body, known as in vitro gametogenesis.

From BBC • Sep. 30, 2025

When that didn’t work, he recommended we move to in vitro fertilization.

From "Becoming" by Michelle Obama