Figure 1.

Amplification of DNA by solid phase PCR. DNA primers (up₁ or up₂) are 5′-end covalently attached to the solid support. Thermocycling the surface (H, hybridisation; E, elongation; D, denaturation) in the presence of a solution of DNA target template, nucleotides and a thermostable polymerase leads to the amplification of DNA molecules on the solid surface. During the initial cycle only interfacial amplification occurs, as DNA target template is present only in solution. During subsequent cycles, in addition to interfacial amplification, surface amplification also occurs between the copied DNA template (5′-end attached to the surface) and attached primers in the vicinity.