The human genome consists of around 3 billion "letters" joined together. Incredible - every single cell contains the entire genome. If you were to pull out the DNA of all human cells as one thread, it would be 150 billion kilometers long. This thread could be stretched from the earth to the sun about 1000 times. The text of our genome contains a lot of important information. It is like a huge library of cookbooks for the cell, which then produces proteins, for example. However, changes in these texts sometimes lead to cells becoming cancer cells. To better understand these processes, scientists are analyzing the significance of these changes.
See and try for yourself how DNA can be extracted from cells, processed and analyzed.
Further information can be found on the website of the Institute of Biochemistry I and the Experimental Nephrology Group.