But it would have to be a science fiction movie, because in real life machines that analyze DNA are about the size of a refrigerator. The global scientific community has set itself the goal of sequencing all of the DNA in the human genome. But to date only about 10 percent of the total has been mapped. Largely, Cornell researchers say, this is because the process being used, gel electrophoresis, is cumbersome and time-consuming. In gel electrophoresis, the DNA to be analyzed is first duplicated to make thousands of copies.
Enzymes chop the DNA chains into many pieces of varying lengths.
The sample is placed at one end of a column of an organic gel and an electric field is applied to the column to make the pieces migrate toward the opposite end. Short pieces move farther and faster than long pieces, so that after a few hours a map is formed showing how the lengths are distributed. Various systems are used to identify the base at the end of each piece, and from this, researchers can identify every position in the chain where each base appears. For accuracy the process must be repeated many times. Craighead and his students hope to speed up and automate sequencing by replacing the organic gel with a tiny solid-state device, called an artificial gel.