Since the cells will adhere to the surface at locations where the complementary nucleotide sequences match, we can program cell adhesion events with a virtually unlimited number of possible coding options. The DNA effectively serves as a molecular barcode on the surface of living cells.

We can pattern a surface with single-stranded DNA containing a specific nucleotide sequence, then coat cells with single-stranded DNA that contains a complementary sequence.

We figured out a way to get living cells to attach where and when we want them to.

Just as DNA chips revolutionized genome analysis, we hope to make cell chips (self-assembled arrays of cells on a thumbnail-sized chip) using our DNA-based cell adhesion strategy. Cell chips could be used as biosensors for detecting the presence of pathogens, or for drug screening, just to name of a few of the many possibilities.

The adhesion of cells is very quick and far stronger than will be needed for most applications. We just let them incubate for 35 minutes, rinse, and we're ready to go. We've kept our cells alive on the chip for up to 25 hours and the same proportion of cells survive using our method as cells cultured under identical conditions.

Now we'll see if we can harness some of the cells' power by incorporating them into a device.