supporting the generation of sequencing data for surveillance of variants. Sanger sequencing is also the "gold standard" for norovirus surveillance methods for the Center for Disease Control and Prevention's (CDC) CaliciNet network. CalciNet is an outbreak surveillance network that was established in March 2009. The goal of the network is to collect sequencing data of circulating noroviruses in the United States and activate downstream action to determine the source of infection to mitigate the spread of the virus. The CalciNet network has identified many infections as foodborne illnesses. This data can then be published and used to develop recommendations for future action to prevent tainting food. The methods employed for detection of norovirus involve targeted amplification of specific areas of the genome. The amplicons are then sequenced using dye-terminating Sanger sequencing and the chromatograms and sequences generated are analyzed with a software package developed in BioNumerics. Sequences are tracked and strain relatedness is studied to infer epidemiological relevance. Challenges Common challenges of DNA sequencing with the Sanger method include poor quality in the first 15-40 bases of the sequence due to primer binding and deteriorating quality of sequencing traces after 700-900 bases. Base calling software such as Phred typically provides an estimate of quality to aid in trimming of low-quality regions of sequences. In cases where DNA fragments are cloned before sequencing, the resulting sequence may contain parts of the cloning vector. In contrast, PCR-based cloning and next-generation sequencing technologies based on pyrosequencing often avoid using cloning vectors. Recently, one-step Sanger sequencing (combined amplification and sequencing) methods such as Ampliseq and SeqSharp have been developed that allow rapid sequencing of target genes without cloning or prior amplification. Current methods can directly sequence only relatively short (300-1000 nucleotides long) DNA fragments in a single reaction. The main obstacle to sequencing DNA fragments above this size limit is insufficient power of separation for resolving large DNA fragments that differ in length by only one nucleotide. Microfluidic Sanger sequencing Microfluidic Sanger sequencing is a lab-on-a-chip application for DNA sequencing, in which the Sanger sequencing steps (thermal cycling, sample purification, and capillary electrophoresis) are integrated on a wafer-scale chip using nanoliter-scale sample volumes. This technology generates long and accurate sequence reads, while obviating many of the significant shortcomings of the conventional Sanger method (e.g. high consumption of expensive reagents, reliance on expensive equipment, personnel-intensive manipulations, etc.) by integrating and automating the Sanger sequencing steps.