Which selection system is used in Puc8 plasmid?
Which selection system is used in Puc8 plasmid?
Which selection system is used in the Puc8 plasmid? Explanation: The identification of recombinants produced by Puc8 plasmid is done by insertional inactivation of lacz’ gene, distinction is done on the basis of the observed colour of the colonies (blue or white).
What is the difference between pBR322 and Puc8?
pUC and pBR322 are both variants of the pMB1 origin. pUC has a few mutations (1 or 2 depending on who you ask) from the pMB1 sequence and these two mutations lead to a 20-35 times difference in copy number – pUC copy number is about 500 per cell while pBR322 is about 20.
What does a lacZ region code for in a Puc8 vector?
pUC8 is present in multiple copies in host E. coli cells. The plasmid has been modified by genetic engineering to contain part of the lac Z gene which codes for β-galactosidase, an enzyme involved in galactoside metabolism.
When lacZ gene is used as a selectable marker?
When the recombinant DNA is inserted into the lac z gene, which codes for the enzyme -galactosidase, it gets inactivated and the recombinant colonies do not produce any colour in the presence of chromogenic substrate so they act as a selectable marker. Non-recombinant colonies produce blue colour colonies.
What is pUC8 plasmid?
pUC8 is a derivative of plasmid pBR322 and filamentous phage M13. Plasmid pUC8:15 bears a 2.3-kb Vitreoscilla chromosomal fragment (Hind IIIHind III) containing the Vitreoscilla hemoglobin gene (vgb).
Is pUC8 a cloning vector?
A cloning vector is defined as a vector used for replication of a cloned DNA fragment in a host cell. These vectors are frequently engineered to contain “ori” – origin of replication sites particular to the host organism. Examples of commonly used cloning vectors are: pUC18, pUC19, pBluescript vectors.
What is the purpose of the LacZ gene in a plasmid cloning vector?
What is the purpose of the LacZ gene in a plasmid cloning vector? The LacZ gene is a selectable marker. Acts as a reporter gene which encodes beta-galctosidase. Expression of the lacz gene causes bacterial host cells carrying pUC18 to produce blue colonies when grown on medium containing a compound Xgal.
Why is LacZ important?
The LacZ protein codes for an enzyme called β-galactosidase, which is an essential part of the metabolism of lactose. It cleaves (separates) a single disaccharide lactose molecule into far more digestible glucose and galactose.
Which selectable marker is incorporated in pBR322 plasmid?
The pBR322 plasmid is a commonly used cloning vector that contains both the ampicillin and tetracycline resistance genes as selectable markers. Escherichia coli cells transformed with pBR322 plasmids have a selective advantage in antibiotic-treated environments.
What is LacZ Alpha in plasmid?
LacZ-alpha fragment is much smaller then the LacZ-omega part and thus can be easily included in a plasmid. It is used to determine if a transformed bacterial colony has received a recombinant plasmid (i.e. +insert) or not.
