Multiplexing in Bioassays

Semiconductor nanoparticles, especially quantum dots (QDs), exhibit favourable optical properties for fluorescence imaging. Simultaneous excitation, without the need for monochromatic light and sharp emission bands allow the development of fast and sensitive multiplex immunoassays. Nano dyes can replace conventional organic dyes to increase the number of signals for multiplexing or be used in combination to form effective FRET-pairs. Advantageous properties like resistance to photobleaching or long fluorescence lifetimes at stable quantum yields and high extinction coefficients add to the benefits of quantum dots. Different strategies for data acquisition and experimental setup can improve conventional staining techniques to make them more sensitive, faster or versatile in multicolour imaging. The photostability allows long term light exposure of quantum dots, increasing the time frame for applications like live cell imaging. We provide a brief overview on current fluorescent tags and hardware suitable for multiplexing.