John Innes Centre 1 article published in JoVE Biochemistry Transient Expression in Nicotiana Benthamiana Leaves for Triterpene Production at a Preparative Scale Michael J. Stephenson1, James Reed1, Bastiaan Brouwer1, Anne Osbourn1 1John Innes Centre Transient heterologous expression of biosynthetic enzymes in Nicotiana benthamiana leaves can divert endogenous supplies of 2,3-oxidosqualene towards the production of new high-value triterpene products. Herein is described a detailed protocol for rapid (5 days) preparative-scale production of triterpenes and analogs utilizing this powerful plant-based platform.