Figure 2From: Exploring possible DNA structures in real-time polymerase kinetics using Pacific Biosciences sequencer data Guanine tetrad and parallel G-quadruplex. A tetrad formed by four guanines shown on left, with hydrogen bonds indicated by thin lines. These tetrads can stack to form G-quadruplexes, shown on the right. The G-quadrupluex shown has all of its strands in parallel, as indicated by the arrows connecting the two tetrads. (Image not to scale.).Back to article page