Strands of nucleic acids hybridize to complementary sequences

(a) The two strands of the DNA double helix can be dissociated by heat in aqueous solutions. Upon cooling under controlled conditions, strands reassociate, or hybridize, with their complement. (b) A cloned copy of the human BAPX1 gene was tagged with a green fluorescent dye. The fluorescent-tagged DNA was then denatured and allowed to hybridize to the chromosomes in a single cell. The fluorescent-tagged clone hybridized to the location on chromosome 4 (green fluorescent regions) where the gene is located.

[(b) C. Tribioliand T. Lufkin, “Molecular cloning, chromosomal mapping and developmental expression of BAPX1, a novel human homeobox-containing gene homologous to Drosophila bagpipe,” Gene, 203, 2, 1997, 225-233, Fig. 6, © Elsevier.