DNA Technology

I. Vectors: Things used to transport genes into cells

A. Plasmid Vectors  1.Plasmid:small circle of bacterial DNA  2. contain only a few genes (non-essential)  3. bacteria will take in plasmids from the environment  4. only bacteria will take in plasmids

B. Virus Vectors  1.Viruses inject DNA into host cell  2. We replace their DNA with genes we want added to a cell  3. Used in gene therapy  4. Treated ‘B in B’ disorder  a. virus put new gene in stem cells  b. stem cells returned to bone marrow  c. 10 of 11 cured (3 later got lukemia)

II. Why cDNA(complimentary DNA)  A) used to put animal gene in bacteria  B) bacteria can’t process mRNA transcripts to remove introns  C) we remove introns from the gene before giving it to bacteria  D) let the human cell do the transcript processing (remove the introns).  E) we use mRNA as a template

III. Making cDNA  A. Get human mRNA for needed protein  B. Add reverse transcriptase that bonds DNA nucleotides to RNA  this DNA is the cDNA  C. Add DNA polymerase that removes RNA nucleotides and replaces them with DNA nucleotides  D. End result = double stranded DNA  can be cut with restriction enzymes  & added to plasmids that bact. take in. 

IV. Probe = used for nucleic acid hybridization  A. Short strand of DNA complementary to gene of interest  B. Tagged with radiolabel or tracer  C. Binds to gene of interest to make hybrid DNA  D. Hybid DNA = any DNA where the 2 sides of the double helix come from different organisms

V. DNA Isolation – isolate the gene you want from the rest of the genome  A. Use probes to label DNA  B. Cut DNA using restriction enzymes  C. Separate DNA using electrophoresis  D. Use only DNA that includes the radiolabeled probe  E. Reduces volume of unwanted DNA

Genetic Engineering  Insert foreign genes into other individual or other species  Modify genes and put back in  Most simple : Bacteria take in plasmids  Most complex :transgenic organisms – zygote modified

Vector plasmids