What is the Difference Between pBR322 and pUC19?

pBR322 and pUC19 are both popular plasmids used as E. Coli cloning vectors, but they have some differences:

1. Size: pBR322 is 4361 base pairs in length, while pUC19 is 2686 base pairs in length.
2. Replication Rate: Due to its larger size, pBR322 has a slower rate of replication compared to pUC19.
3. Origin of Replication: pBR322 has two origins of replication, one derived from the ColE1 plasmid and another from the pMB1 plasmid, whereas pUC19 has a single origin of replication derived from the pMB1 plasmid.
4. Copy Number: pBR322 is a low copy number plasmid, while pUC19 is a high copy number plasmid.
5. Antibiotic Resistance Genes: Both plasmids have an ampicillin resistance gene (AmpR) as a selectable marker. pBR322 also carries the tetracycline resistance gene (tetR).
6. Lambda Genes: pUC19 has two Lambda genes (bla and lacZ), which encode for AmpR and β-galactosidase, respectively.

Both plasmids are used for molecular cloning and manipulation, but pUC19 is more commonly used due to its high copy number and faster replication rate.

Comparative Table: pBR322 vs pUC19

Here is a table summarizing the differences between pBR322 and pUC19:

Both pBR322 and pUC19 are popular plasmids used as E.Coli cloning vectors, with multiple restriction sites and an origin of replication (ori). pBR322 is a low copy number plasmid vector, while pUC19 is a high copy number plasmid vector. The difference in plasmid size affects the plasmid copy number, with larger plasmids tending to have a lower copy number.