1. A method to detect the presence of single nucleotide polymorphisms (SNPs) of a nucleic acid in a sample containing the nucleic acid, comprising: (a) contacting in a solution said sample with at least eight unlabeled oligonucleotides under conditions permitting hybridization between said oligonucleotides and the nucleic acids in said sample; (b) generating primer extension products, each product labeled with one of at least eight different fluorescent dyes by primer extension reactions in the presence of ddNTPs, each ddNTP labeled with one of at least eight different fluorescent dyes; and (c) detecting the SNPs by detecting the primer extension products, each product labeled with one of at least eight different fluorescent dyes by laser-induced fluorescence using a galvanometer in a step and stare mode and a spectrograph to detect the fluorescence from each of said at least eight different fluorescent dyes.