Technical Notes for Sequencing Difficult Templates

There are a number of template types that are generally recognized as being difficult to sequence. These can include sequences with a high guanine-cytosine (G/C) content, sequences that are very rich in adenine/thymine (A/T), sequences with a marked secondary structure, or large regions of homopolymer. There is no one solution to these difficulties; however, there are a number of approaches that can be used to improve the quality of sequencing data obtained from each type of problem sequence.