Basic features of plasmids :
● Replication within the host cells
● Small size, ideally < 10 kb
● Selective marker, resistant gene
● Multiple cloning sites(MCS)
Figure2.1 Plasmids: independent genetic elements found in bacterial cells
Figure2.2
The use of antibiotic resistance as a selectable marker for a plasmid.
Firgure2.3
Replication strategies for (a) a non-integrative plasmid, and (b) an episome
(integrative plasmid)
（附加体 or 游离基因：能可逆地整合进入宿主染色体的质粒）
