On the application of integer arithmetic in nucleotide sequence analysis.

A method exploiting quaternary integer arithmetic for the rapid comparison of nucleotide sequences is proposed. A central feature of the method is the identification of a suitable integer arithmetic operation which, operating on two numerical strings (representing two sequences), yields an output string unambiguously related to the number of matching nucleotides in the compared sequences. The number of matching nucleotide bases in compared sequences can be determined without having to make individual base by base comparisons. The method is a general extension of the algorithm previously described in the code UNIREP. The rules governing integer arithmetic as applied to nucleotide sequences are discussed.