Chapter 20DNA Technology &

Genomics

Genetic engineering

• Manipulation of genetic material for practical purposes has begun industrial revolution in biotechnology – use of living organisms or components to do practical tasks

Tools of genetic engineering1) restriction enzymes – bacterial enzymes which

protect bacteria against intruding DNA from other organisms by cutting up foreign DNA

• 1st found in late ’60’s

• Recognize short specific nucleotide sequences

in DNA & cut at specific points within these sequences

• 100’s & ~100 different specific recognition sequences

Tools of genetic engineering

• Sequences are symmetric; 4-8 nucleotides on both strands, but running in opposite directions

ex: 5’ GAATTC 3’

3’ CTTAAG 5’

Tools of genetic engineering

2) gel electrophoresis – separates NA or protein

by size & electric charge by measuring rate

of movement through an electric field

Applications of biotechnology

• Diagnosis of disease

• Gene therapy

• Pharmaceutical products

• Forensics

• Agricultural uses

• Cloning