the ruthenium compound is excited by a burst of laser light. this dye can bind in only two ways to dna. it's the surface features of the dna molecule that determine where it will bind. by measuring the different glows, it is hoped we can gain a more detailed understanding of dna. for this experiment, we're going to flash the ruthenium dna sample in a very short instant and then watch the decay of the glow from the ruthenium bound to the dna complex as a function of time. it will only flash for an instant. let's try it. here's the sample. there was one flash. it will do it again. there it went again. let's see what the computer's seeing in all this. now we can see this. here's the spectrum after short periods of time. every four billionths of a second, we can take that spectrum and watch the color and use that information to get dynamic information about how the complexes are binding to dna. this becomes our probe, our way of looking in detail at the structure of dna, doing it in ways we can't do with our eyes. the next step is to design new day