Fluorescent magnetic emulsion droplets: Potential material for multiplexed optical coding of biomolecules

Fluorescent magnetic microbeads can be potentially used in optical coding of biomolecules. The currently commercially available microbeads so far suffer polydispersity in both size and fluorescence intensity. Large statistical fluctuations in intensity level are quite detrimental for their use in optical coding applications. To optimize them for multiplexed optical coding of biological molecules, besides monodispersity, statistical fluctuations in intensity of beads need to be maintained as low as possible (<1% and less) in order to obtain a large number of codes. Here, we show that fluorescent and magnetic droplets synthesized through a simple and elegant oil-in-water microemulsion technique can have statistical fluctuations as low as <1% with a number of fluorescent labels.