Chromosome-walking begins with a recombinant phage or BAC clone obtained from a library that contains large inserts representing an entire eukaryotic genome. The key concept is to use the sequence of the neighbouring landmark as a probe to recognize a second set of clones that partly covers the marker clone possessing the landmark. But, this extends out from it towards the target or away from the target.
The new set of clones from the end fragments can be used as probes for identifying a third set of overlapping clones from the genomic library. Thus, the researchers identified the clone containing the molecular markers that are more strongly connected to the CF (cystic fibrosis) trait.
The researchers also found that the fragment he or she be utilizing as probe to recognize neighbouring sequences. That would be hybridized to a lot of non-overlapping clones and the type of recurring sequences might not be used in a chromosome walking. It’s because the repeated sequence may possibly present in various genomic positions and is not possible to find out which was the correct one.