Later in 1968, it was decided that the term plasmid should be adopted as the term for extrachromosomal genetic element, and to distinguish it from viruses, the definition was narrowed to genetic elements that exist exclusively or predominantly outside of the chromosome and can replicate autonomously.
Posteriormente, en 1968, decidiuse que o termo plásmido debería adoptarse como termo para os elmentos xeneticos extracromosómicos, e para distinguilos dos virus, a definición foi restrinxida a elementos xenéticos que existen exclusivamente ou predominantemente fóra do cromosoma e poden replicarse autonomamente.