2.2. Universal Fingerprinting Chip (UFC-13)
An oligonucleotide probe is a short piece of single-stranded DNA that is complementary to the target to be measured on the microarray. A set of 15,264 13-mer oligonucleotide sequences constitutes the UFC-13 chip that was used for hybridizing with all the Bacillus anthracis genomes strains selected. The UFC-13 includes: (a) a 35%–65% G + C content; (b) between-sequences differences have been maximized such that all sequences differ in at least three bases from each other; and (c) the sequences Tm ranges between 52 °C and 68 °C. Bacillus anthracis has an average of 5.5 Mb, and the size of the 13-mer probes is suitable for bacterial genomes [13].
microarrays-04-00084-t001_Table 1 Table 1  Bacillus anthracis genomes used in this study.   * Related GenBank Project (Accession).

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