The electronic microchip is a recently developed technology for the fast and reliable detection of known single-nucleotide polymorphisms (SNPs) in the genome. The DNA fragment to be analyzed is directed electrophoretically into the chip, and then it is hybridized with fluorescent-tagged DNA probes specific for the mutant and wild-type sequences. The presence or absence of the mutation is detected by the fluorescence signal. Electronic stringency provides quality control for the hybridization process and ensures that any bound pairs of DNA are truly complementary; the microchip can be easily customized by the end user, allowing for assembly of specific probes onto the microchip to perform individualized analyses. Assays for 10 frequent mutations in the beta-globin gene causing beta-thalassemia and sickle cell anemia are presented that can be applied, in turn, to population screening or family study and prenatal diagnosis in single cases.