Sensitive detection of genes by sandwich hybridization and time-resolved fluorometry.
Europium has been used as a non-radioactive marker in immunoassays as this metal can be detected with high sensitivity by time-resolved fluorometry. In this work streptavidin labeled with europium was used to detect biotinylated probes in a sandwich nucleic-acid hybridization assay with microtitration strips as the solid phase. pBR 322 plasmids were detected with a sensitivity of 4 x 10(5) molecules. As the sample is added in solution in sandwich hybridization, fast and simple sample pre-treatment can be used without encountering background problems. The method was applied to test bacterial samples of uropathogenic Escherichia coli strains for the presence of the beta-lactamase gene.
Dahlén
P
P
Wallac Oy, Turku, Finland.
Syvänen
A C
AC
Hurskainen
P
P
Kwiatkowski
M
M
Sund
C
C
Ylikoski
J
J
Söderlund
H
H
Lövgren
T
T
D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D001710:Biotin; D004247:DNA / Q000032:analysis; D004926:Escherichia coli; D005063:Europium; D005470:Fluorometry / Q000379:methods*; D005796:Genes; D005820:Genetic Testing; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D019809:Streptavidin; D001618:beta-Lactamases / Q000235:genetics
D001426:Bacterial Proteins; D005063:Europium; D001710:Biotin; D004247:DNA; D019809:Streptavidin; D001618:beta-Lactamases