For single cell sequencing, scientists first have to isolate the cell nuclei. When these nuclei pass over a microfluidic chip, they are packed into small aqueous droplets along with a barcode. In the droplets, the barcode is then coupled with the RNA from the nucleus - the transcripts that are generated when the genes are read from the DNA. This way, the RNA can be assigned to the individual cell nuclei after sequencing. Credit: Eric Lindberg, MDC