View source for Plasmid backbones/Overview

[[Image:BioBrickbackbonevspart.png|right]]

Plasmids are circular, double-stranded DNA molecules typically containing a few thousand base pairs that replicate within the cell independently of the chromosomal DNA.  Plasmid DNA is easily purified from cells, manipulated using common lab techniques and incorporated into cells.  Most BioBrick parts in the Registry are maintained and propagated on plasmids.  Thus, construction of BioBrick parts, devices and systems usually requires working with plasmids.

'''Note''': In the Registry, plasmids are made up of two distinct components: 
#the BioBrick part, device or system that is located in the BioBrick cloning site, between ''(and excluding)'' the BioBrick prefix and suffix.  
#the plasmid backbone which propagates the BioBrick part.  The plasmid backbone is defined as the sequence beginning with the BioBrick suffix, including the replication origin and antibiotic resistance marker, and ending with the BioBrick prefix.  [Note that the plasmid backbone itself can be composed of BioBrick parts.]

Many BioBrick parts in the Registry are maintained on more than one plasmid backbone!