Isolating Target Genes

Question 1

What are the 2 methods of isolating target genes?

Answer 1

restriction enzymes and reverse transcriptase

Question 2

How do you isolate target genes with restriction enzymes?

Answer 2

• DNA contains pallindromic sites e.g. reads something forwards and the same backwards
  e.g. CTTAAG - GAATTC
• restriction enzymes will cut the dna at the
  restriction sites.
• if there is a restriction site at either side of the target gene….
  
  • restriction enzymes can be used to cut it out
• using a restriction enzyme will leave sticky ends (unpaired bases)
• we can use the sticky end to cut and paste DNA

Question 3

How do you isolate target genes using reverse transcriptase?

Answer 3

• cells only have 2 copies of each gene (in the nucleus) - hard to access
• enzyme that does transcription backwards
  mRNA -> cDNA by Reverse transcriptase
• ## it has no introns