Deoxyribonucleic Acid Gallery

DNA nucleosome, molecular model

DNA nucleosome. Molecular model of a nucleosome, the fundamental repeating unit used to package DNA (deoxyribonucleic acid) inside cell nuclei. DNA is the molecule that carries the genetic code that forms the basis of all life on Earth. It is a long molecule and has to be tightly coiled to fit inside the nucleus. DNA's double helix structure is shown here as a coiled orange spiral. The DNA is coiled round a core of histone proteins (multicoloured ribbons). The ribbons represent the molecular structure of the histone proteins. Each set of two DNA loops around a histone core is known as a nucleosome. Further compacting and packaging (not seen here) form the denser forms of chromatin, and eventually the cell's chromosomes

© LAGUNA DESIGN/SCIENCE PHOTO LIBRARY

DNA Double Helix with Autoradiograph

Conceptual computer illustration of the DNA double helix together with a graphic representation of an autoradiograph display. The pattern of the DNA autoradiograph bands is unique to each individual, but some bands are shared by related people, such as a parent & child. DNA fingerprints can be used to prove conclusively whether people are related. The double-helix model of DNA structure was first published in the journal Nature by James D. Watson and Francis Crick in 1953, based upon the crucial X-ray diffraction image of DNA labeled as "Photo 51", from Rosalind Franklin in 1952. The structure of a double-helix elucidated the mechanism of base pairing by which genetic information is stored and copied in living organisms. Genetic fingerprinting and DNA profiling was developed by Dr. Alec Jeffreys and his team in 1985

© DAVID PARKER/SCIENCE PHOTO LIBRARY

Grapevine genome sequencing

Grapevine genome sequencing. Data from a gelelectrophoresis experiment to sequence the PinotNoir grape ( Vitis sp. ) genome. This technique isused to separate, in sequence, nucleotide basesfrom DNA (deoxyribonucleic acid) fragments. DNAcontains 4 bases (adenine, cytosine, guanine andthymine), which are represented here by differentcolours. The DNA fragments are placed in a porousgel that has an electric current applied to it.The nucleotides move down the gel according totheir size. After the process has run the basesappear as bands on the gel. The sequences of basesmake up genes, which encode an organism's geneticinformation. Photographed at the AgriculturalInstitute of San Michelle all'Adige, Trento, Italy

© Mauro Fermariello/Science Photo Library