4.2 Size limitations

PCR works readily with DNA of lengths of two to three thousand base pairs, but above this length the polymerase tends to fall off and the typical heating cycle does not leave enough time for polymerisation to complete. It is possible to amplify larger pieces of up to 50,000 base pairs, with a slower heating cycle and special polymerases. The polymerase may be fused to a DNA-binding protein, making it "stick" to the DNA longer or it may be specially engineered to increase thermostability.

© SCBC 2007