Miniaturized PCR chips for nucleic acid amplification and analysis: latest advances and future trends

Zhang, Chunsun; Xing, Da

Chamber-based PCR chips are constructed as closed systems where the reaction chamber(s) are actually microfabricated on the chip. Their design does not differ significantly from the model presented by Northrup et al. (84) . Recently, Guttenberg et al. proposed a completely different approach to handle small-scale sample using a hydrophobic/oleophobic surface to provide virtual fluid confinement (77) . The concept of virtual reaction chamber (VRC) ( Figure 1C ) was applied for the first time on the PCR chip in 2005, in which each PCR sample droplet was covered with a drop of mineral oil. Neuzil et al. further optimized this approach by placing a disposable microscope glass cover slip on top of a silicon chip to eliminate cross-contamination between samples (79, 80) .