Integrated PCR amplification and detection processes on a Lab-on-Chip platform: a new advanced solution for molecular diagnostics

Background: Several microdevices have been developed to perform only a single step of a genotyping process, such as PCR or detection by probe hybridization. Here, we describe a Lab-on-Chip (LoC) platform integrating a PCR amplification microreactor with a customable microarray for the detection of sequence variations on human genomic DNA. Methods: Preliminary work was focused on developing the single analytical steps including PCR and labeling strategies of the amplified product by conventional reference systems. The optimized protocols included a 1:4 forward: reverse primer ratio for asymmetric PCR, and Cy5-dCTP multiple incorporation for the generation of a labeled PCR product to be hybridized to complementary probes bound to the chip surface. Results: Final conditions were applied to the fully integrated LoC platform for the detection of the IVSI-110 G) A mutation in the human beta-globin (HBB) gene associated with beta-thalassemia, used as a model of genetic application, allowing for correct genotyping of 25 samples that were heterozygous, homozygous or wild-type for this mutation. Conclusions: The overall results show that the present platform is very promising for rapid identification of DNA sequence variations in an integrated, cost effective and convenient silicon chip format. Clin Chem Lab Med 2010;48:329-36.