[1] It is one of the gene mapping techniques which can determine the sequence of DNA base pairs with high accuracy.
[6] If the actual positions of genes which control certain phenotypes are known, it is possible to resolve genetic diseases by providing advice on prevention and developing new treatments.
In this category, most mapping methods involve generating a somatic cell hybrid panel, which is able to map any human DNA sequences, the gene of interest[clarification needed], to specific chromosomes of animal cells, such as those of mice and hamsters.
[5] This provides evidence on whether the markers are located on the same human chromosome fragment, and hence the order of gene sequence.
Since their hierarchic structure is less condensed comparing to prometaphase and metaphase chromosomes, the standard in situ hybridization target, a high resolution of physical mapping could be produced.
However, naturally extended chromosomes might be folded back and produces alternative physical map orders.
The method suggests the order of desired regions on the DNA sequence by analyzing the partial overlaps and gaps between yeast artificial chromosomes (YACs).
[9] During the progress, a chromosome is obtained from a hybrid cell and cut at rare restriction site to produce large fragments.
The fragments will be separated by size and undergo hybridization, forming the macrorestriction map and different contiguous blocks (i.e. contigs).
This approach has easier experimental handling, but more difficult in terms of the combinatorial problem required for mapping.
This technique uses one restriction enzyme to digest the desired DNA in separated experiments with different durations of exposure.
To ensure there is a minimum set of clones that form one config for a genome (i.e. tiling path), the library used will have five to ten times redundancy.
Ongoing projects that determine DNA base pair sequences, namely the Human Genome Project, give knowledge on the order of nucleotide and allow further investigation to answer genetic questions, particularly the association between the target sequence and the development of traits.