Sequenzierungszyklen

Sequenzierungszyklen, also known as sequencing cycles, refer to the fundamental repeating steps in most modern DNA sequencing technologies. These cycles are the engine that drives the process of determining the order of nucleotides (adenine, guanine, cytosine, and thymine) within a DNA molecule. The specific implementation of these cycles varies between different sequencing platforms, but the core concept remains the same: a cyclical process of detection and chemical reaction.

Typically, a sequencing cycle begins with the introduction of fluorescently labeled nucleotides. These nucleotides are designed to be incorporated into a growing DNA strand, but only one type of nucleotide can be added at each position. After incorporation, a detection step occurs, where the fluorescent signal emitted by the incorporated nucleotide is captured by a scanner or camera. This signal's color corresponds to a specific nucleotide base. Following detection, the fluorescent tag is chemically removed, allowing the process to repeat with the introduction of the next set of labeled nucleotides. This cycle repeats millions or billions of times, building up a complex dataset of signals that are then computationally analyzed to reconstruct the original DNA sequence. The number of cycles directly correlates with the length of the DNA fragments being sequenced and the desired accuracy. Longer sequencing runs with more cycles generally yield more information but also require more time and resources.