dsDNA-coated quantum dots.

Because of their unique spectral properties, quantum dots (QDs) have recently proved useful as fluorescent labels for biosensing probes. We developed a versatile QD label by modifying dsDNA with biotin and thiol groups at opposite ends and attaching it to quantum dots via a metal-thiol bond. These dsDNA-coated QDs fluorescently label their targets through biotin-streptavidin binding and show excellent histological results when used to detect biotin-labeled chromosome probes. The dsDNA coating also circumvented the common problems of aggregation and steric hindrance that occur with other QD probes.