Plasmid backbones/Version 3/Features

1. A complete BioBrick® cloning site for easy cloning and assembly of BioBrick parts.
2. Terminators flanking the BioBrick® cloning site to insulate the vector from read-through transcription originating in the cloned BioBrick® part, device or system.
3. Primer binding sites for the standard BioBrick® verification primers VF2 (BBa_G00100) and VR (BBa_G00101). These primers are located for convenient sequencing and [http://openwetware.org/wiki/Colony_PCR screening by colony PCR] of cloned BioBrick® parts, devices, and systems.

Plasmid backbones are distributed by the Registry with a default insert. There are just a handful of default plasmid inserts used in the Registry. Many the available plasmid backbones have the ccdB positive selection marker (BBa_P1010) as the default plasmid insert within the BioBrick® cloning site. The ccdB gene ensures that when assembling two BioBrick® parts together, the uncut plasmid is not transformed. However, inclusion of the ccdB gene means that these vectors must be propagated in a ccdB tolerant strain, such as E. coli strain DB3.1 (BBa_V1005).