Description
Plasmid DNA pBR322, lyophilized, Storage temp. -20 °C
The following plasmid DNA was prepared in low nuclease host bacteria and isolated through ion exchange chromatography. It is available in supercoiled form (ccc-form >95%) and, as a high-purity DNA (OD260/280 > 1,70), it is ideal for different applications:
- Controlling transformation efficiency
- Comparison with plasmid ccc-forms of unknown size
- Cloning DNA-fragments
- Restriction (Preparing DNA-length markers)
- Calibrating DNA-separating or DNA-preparing processes or equipment
- Blocking DNA-chips with plasmid DNA of a defined sequence
The circular sequence was numbered in such a way that 0 lies in the middle of the singular EcoR l restriction site. The copy number of pBR322 is limited by the gene product of rop to 20 copies per cell. However, by adding chloroamphenicol (final concentration 170 µg/ml) to log-phase cultures and then incubating for 8 hours, the copy number can be increased considerably.
General properties:
- OD260/280: >1,70
- Genomic DNA: <2 %
- oc form: <3 %
- ccc form: >95 %
- Base pairs: 4361