Figure 1. Sequencing DNA fragments. Left, principle of the chain-termination method. Right, sequencing DNA fragments on a gel with 96 lanes. The four colors, blue, green, yellow, and red, represent the four bases C, G, T, and A of DNA. (Diagram and photograph: Anne Kemmling, Goettingen.)

Figure 2. The genome of Clostridium tetani in a circular presentation on the basis of the sequence. The chromosome is 2 788 250 base pairs long. The genes on both strands are colored in blue and green. The origin of replication is at twelve o'clock. The plasmid consists of 74 082 base pairs. The gene for the tetanus toxin (red) is located between 11 and 12 o'clock. The other “red” gene between 6 and 7 o'clock codes for a protein-degrading collagenase. (Holger Brueggemann et al., Proceedings of the National Academy of Sciences 100, 1316–1321, 2003.)

Figure 3. The proteome of Bacillus subtilis. Proteins are separated by two-dimensional gel electrophoresis. Colors represent patterns of the synthesis of proteins under certain stress conditions: heat shock, red; ethanol shock, yellow; oxidative stress, blue; all three stress factors, green. (Photograph: Michael Hecker and Decodon GmbH, Greifswald, Germany.)