Most Americans say, He will live! After all, the thumbs-up sign is a positive thing. It's how we encourage our friends and silently show approval. But to the ancient Romans, a thumbs up mimicked the upward thrust of a sword through the heart. It meant, kill. A thumbs-down meant put your sword down. So where did this confusion about thumbs come from?
Freebase(0.00 / 0 votes)Rate this definition: Transfection. Transfection is the process of deliberately introducing nucleic acids into cells. The term is used notably for non-viral methods in eukaryotic cells.
Medical Definition of PROVIRUS. : a form of a virus that is integrated into the genetic material of a host cell and by replicating with it can be transmitted from one cell generation to the next without causing lysis.â proÂ·viÂ·ral \-rÉl\ adjective. ADVERTISEMENT. a form of a virus that is integrated into the genetic material of a host cell and by replicating with it can be transmitted from one cell generation to the next without causing lysis. Next Word in the Dictionary: provision (noun) Previous Word in the Dictionary: proving ring All Words Near: provirus.