In genetics,<unk> , also known as<unk>  cloning, is a method used for<unk>  long DNA strands. It is named by analogy with the rapidly-expanding, quasi-random firing pattern of a<unk> .
Since the chain termination method of DNA<unk>  can only be used for fairly short strands, longer sequences must be subdivided into smaller fragments, and subsequently re-assembled to give the overall sequence. Two principal methods are used for this: chromosome walking, which progresses through the entire strand, piece by piece, and<unk> , which is a faster but more complex process, and uses random fragments.
In<unk> , DNA is broken up randomly into numerous small segments, which are sequenced using the chain termination method to obtain reads.  Multiple overlapping reads for the target DNA are obtained by performing several rounds of this fragmentation and<unk> . Computer programs then use the overlapping ends of different reads to assemble them into a contiguous sequence.
For example, consider the following two rounds of<unk>  reads:
In this extremely simplified example, the four reads can be assembled into the original sequence using the overlap of their ends to align and order them. In reality, this process uses enormous amounts of information that are rife with ambiguities and<unk>  errors. Assembly of complex genomes is additionally aggravated by the great abundance of repetitive sequence, meaning similar short reads could come from completely different parts of the sequence.
Many overlapping reads for each segment of the original DNA are necessary to overcome these difficulties and accurately assemble the sequence. For example, to complete the Human Genome Project, most of the human genome was sequenced at 12X or greater coverage; that is, each base in the final sequence was present, on average, in 12 reads. Even so, current methods have failed to isolate or assemble reliable sequence for approximately 1% of the (euchromatic) human genome.
Shotgun sequencing
Nucleic acid amplification technique
Molecular cloning
DNA sequencing
Southern blot
Sequencing
BET theory
Nucleic acid hybridization