Patent ID: 6919445

Claim:
A method of polynucleotide sequencing comprising the steps of: forming a mixture of a first, a second, a third, and a fourth class of polynucleotides such that: each polynucleotide in the first class includes a 3′-terminal dideoxyadenosine and is labeled with a first dye; each polynucleotide in the second class includes a 3′-terminal dideoxycytidine and is labeled with a second dye; each polynucleotide in the third class includes a 3′-terminal dideoxyguanosine and is labeled with a third dye; and each polynucleotide in the fourth class includes a 3′-terminal dideoxythymidine and is labeled with a fourth dye; wherein at least one of the first, second, third, or fourth dyes is a dibenzorhodamine compound comprising the structure including nitrogen- and aryl-substituted forms thereof; the other of the dyes being spectrally resolvable from the dibenzorhodamine dye(s) and from each other; electrophoretically separating the polynucleotides thereby forming bands of similarly sized polynucleotides; illuminating the bands with an illumination beam capable of causing the dyes to fluoresce; and identifying the classes of the polynucleotides in the bands by the fluorescence spectrum of the dyes.