Researchers then check the contaminants by putting them on a specific cell type, harvested in a laboratory dish, to observe if the contaminants can get in to the cells. The very best candidates are tested in animals then. However, that is a gradual procedure and limitations the amount of contaminants that may be attempted. The problem we’ve is we are able to make far more nanoparticles than we are able to check, Anderson says. To overcome that hurdle, the analysts decided to put barcodes, comprising a DNA series around 60 nucleotides, to each kind of particle.