of measuring the quantity of a variety of analytes, including DNA, RNA, and
protein, by comparison with a known standard; can be used to determine the
number of copies of a sequence of DNA (i.e., to test for duplication and
deletion mutations) either by visual comparison of band intensity or numerical
quantification by densitometry. If extra copies of a gene are present, intensity
is greater than 100% on a gel or film; whereas, if one copy of the gene is
missing, the intensity is approximately 50%.
Definition from: GeneReviews
from the University of Washington and the National Center for Biotechnology Information
See also Understanding Medical Terminology.