PGEM3-Z is a plasmid vector derived from pUC vectors. It contains the ampicillin resistance gene (ampR) and LacZ gene with clustered restriction sites, similar to pUC vectors. PGEM3-Z is commonly used for in vitro transcription, protein expression, and DNA cloning due to its high copy number, ability to identify inserts through blue-white screening, and flexibility afforded by clustered restriction sites.

1. PGEM3-Z
BY:- VIVEK KUMA5R
M.SC MICROBIOLOGY
BANGALORE UNIVERSITY

2. PLASMIDS
A Plasmid is a self
replicating,double stranded ,
extrachromosomal DNA’s
maintained as independent
molecules by the most of the
bacterial genera.
LEDERNBERG IN 1952 Coined
the term “PLASMID”.

4. CLONING VECTORS BASED ON
E.COLI PLASMIDS
EX: PUC 8 PLASMID
• pUC8 plasmid is derived from
pBR322, remaining only the replication
origin and the ampR gene.
• All coding sites are cloning sites are
clustered into a short segment of the
Lac Z gene carried by pUC 8.

6.  Used in invitro transcription and protein expression.
pGEM3-Z is having similarity with a pUC vector because
of the presence of the ampR genes and Lac Z gene
containing a cluster of restriction sites.

9. ADVANTAGES
• High copy number.
• Identification can be achieved by single step by plating on agar
medium containing amplicillin and X-gal .
• Time consumption is less.
• pUC vectors carry different combinations of restrictions site
and show greater flexibility of DNA fragment that can be
cloned.
• Clustering of restriction sites that show greater flexibility
allows a DNA fragment with two different sticky ends to be
cloned without involving linker attachment.
• DNA cloned into a member of the pUC series can be transferred
directly to its M13 mp counterpart, because of the same
restriction sites clusters and it can be analyzed by DNA
sequencing or in vitro Mutagenesis.