Detection of nucleotide mismatches and specificity of immobilization via hybridization with fluorescein-labeled complementary oligonucleotides. Lane 1, H2N-(CH2)5-OPO3-d(CTC CTG AGG AGA AGG TCT GC) (entry 5, Table 1); lane 2, H2N-(CH2)5-OPO3-d(CTC CTG AGG CGA AGG TCT GC) (entry 6, Table 1); lane 3, H2N-(CH2)5-OPO3-d(CTC CTG CGG AGA ACG TCT GC) (entry 10, Table 1); lane 4, H2N-(CH2)5-OPO3-d(CTC CTG CGG CGA ACG TCT GC) (entry 11, Table 1); lane 5, H2N-(CH2)5-OPO3-d(TTT TTT TTT TTT TTT TTT TT) (entry 12, Table 1). Hybridization was carried out using FAM-d(GCA GAC CTT CTC CTC AGG AG) (entry 8, Table 1) followed by laser scanning.