Identification of p53 gene by using CdSe/ZnS conjugation and hybridization

Recently Quantum Dots (QDs) have been of great interest due to their unique optical properties such as size-dependent, symmetric, narrow, and stable emissions, allowing for prolonged observation and multiplexing. We have prepared oligonucleotide conjugated to QD as a probe to detect p53 tumor suppressor gene related to hereditary cancer. QDs with carboxyl functional group have been conjugated to thiol-modified oligo nucleotides, which have been used as a hybridization probe for p53 gene. Target gene was added and hybridized with the QD bound probe. The conjugation of QD and thiolated oligonucleotide was stained by gel electrophoresis using Etrium Bromide (EtBr) as intercalating dye. Fluorescence resonance energy transfer (FRET) has been observed between QD and intercalating dye (Propidium Iodide) after hybridization of target and probe. FRET efficiency was increased with the increase of dye and DNA concentration. This shows the possibility of specific detection of low concentration of unlabeled complimentary DNA via quantum dots.