Description

8 distinct condensed phases of DNA, shown in different colors. Droplets of different “species” will not merge, but droplets of the same species will. 8 coexisting droplet types is more than has been demonstrated for this type of system, and is the result of turning off 28 interactions!

DNA nanoparticles were carefully designed to precisely tune interactions between particles, such that there was attraction between like-particles and no attraction between particles of different species. A multiplexed imaging strategy, where fluorescent dye and the labeling intensity were varied, was used. For example, A- and B-type particles were both tagged with Cy5, but 2% of A-particles were tagged with Cy5 while 4% of B-particles were tagged. The epifluorescent Cy5 image, capturing all the intensity of each droplet, was analyzed to determine the intensity/volume of each droplet, making it possible to identify which droplets were comprised of A-vs. B-particles. Two other fluorescent dyes were used with varied intensities. There are over 3000 droplets in this approximately 2mm square.