This information can be compacted into 2000 base pairs of DNA or be as complex as two million base pairs. A total of three billion base pairs will give rise to our estimated 80,000-100,000 genes. It is only after we understand the principles behind DNA that we can begin to think about the mapping of our genetic sequence. Using traditional genetics and insights from the fields of molecular biology and biochemistry, mapping seeks to determing the position and spacing of genes or other landmarks. Essentially, there are two types of mapping, physical and genetic.
Genetic mapping divides the chromosomes in two bands.
Here scientists seek to assign certain genes to specific chemical bands. Diseases can also be assigned to the various bands with analysis of genetic findings. The higher frequency in which they are inherited together often symbolizes the closer they lie to each other on the chromosomes. Before scientists construct the maps often they must know the genetic sequence behind it . The Sanger Method is a genetic mapping technique often used due to its precision.