MAKING_LIFE 2014 - 2015

Restriction dsc05194 620x413
Restriction enzymes
posted by sarah on 16 March 2016

Paul Vanouse's talk was concerning DNA imaging, microorganisms and restriction enzymes.

Restriction enzymes cut double stranded DNA at specific recognition sites. These enzymes were discovered in bacteria. They use them to cut foreign DNA (viral) out of their genome, to prevent self cutting the restriction sites in their own genome which are methylated and cannot be detected by the enzymes (see
The recognition sites are normally 4-8 base pairs long and form an inverted repeat. The enzyme cuts DNA either at the same point leaving blunt ends or in a staggered fashion leaving DNA overhangs, the so called 'sticky hands'.
Restriction enzymes are extremely useful in genetic analysis (DNA fingerprint) and genetic engineering (cloning of genes into a vector). After the introduction Paul gave us the challenge to find the cutter of the lambda DNA, a bacteriophage.
The suspects were:

  • EcoRI gaattc

  • HindIII aagctt

  • PstI ctgcag


So we went to the lab bench and started pipetting.