What is the difference in a marker and an allele?
The particular region of the DNA that is analyzed is often referred to as a locus or marker. It can be thought of as the address on the chromosome for example, DYS 441. The value detected at the marker is the allele value. For example, a segment repeated 15 times at marker DYS441 is written as (marker) DYS441 (allele) 15. When comparing multiple individuals to determine if a common ancestor is shared, the allele values of each of the markers tested are compared.
