So what we basically do is we allow these cells, the equalized cells, to replicate, to divide and replicate and we extract the DNA. Then we centrifuge that DNA and we analyze our DNA. So what they obtained was the following three photographs. So each of these photographs basically describes the band that correlates to the DNA molecules that were extracted. So if we take out our DNA molecule from our equalized cell that has not yet divided, then what we'll see is a single band that describes a single type of DNA molecule. Now, by the way, as we go this way from left to right along the x axis, we increase in density.