Forensic Biology 1950 to Present
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DNA typing, since it was introduced in the mid-1980s, has revolutionized forensic science and the ability of law enforcement to match perpetrators with crime scenes. Thousands of cases have been closed and innocent suspects freed with guilty ones punished because of the power of a silent biological witness at the crime scene. DNA fingerprinting or DNA typing (profiling) as it is now known, was first described in 1985 by an English geneticist named Alec Jeffreys.
1953: On April 1, the Scientific Laboratory moved from Broadway to a new, purpose-built, 7,500-square-foot structure at 8 Nolan Road in Albany, left. The new building included many features designed to be conducive to scientific criminal investigations, such as special rooms for lie detector examinations, serological analyses, microscopic examinations and other specialized work, as well as a museum for criminal exhibits, a motion picture projection room, a photographic studio and physical laboratory.
1964: In May, the Division opened its new headquarters building, left, on the State Office Building Campus in Albany, consolidating its administrative offices, Pistol Permits Bureau and Crime Laboratory in a single, central location. The move was part of a sweeping program of building assessment, re-evaluation, consolidation, construction and modernization implemented by Superintendent Arthur Cornelius Jr.
This was discovered in 1982 by latent fingerprint examiners at the U.S. Army Criminal Investigation Laboratory in Japan. This method is particularly useful in developing latent prints on household items such as plastic bags, aluminum, and rubber bands. Cyanoacrylate is the chemical used in Superglue. In addition to black powder, a white powder is used to develop latent prints. This white powder is composed of the chemical ninhydrin. The traces of amino acids present in perspiration bind with the ninhydrin and the prints begin to appear in about an hour. Ninhydrin is the most common chemical reagent used for developing latent prints on paper. Silver nitrate reacts with the sodium chloride in perspiration to develop latent prints in much the same way that ninhydrin reacts with amino acids. The last of the commonly used latent print development methods is the Gentian violet method. Gentian violet or crystal violet is used to stain nonliving epidermal cells or perspiration that has been left on almost any type of surface. Tape is used to remove whatever might be present from the surface to be sampled. It is then run through the solution of gentian violet. The second type of print is the visible print. Obviously, visible prints are the most legible. Fingers stained with blood or ink found can form visible prints. The third type, the plastic print, is quite easy to read as well because it is an impression made on a soft surface such as soap, putty, or wax.
Since the mid-1980s, DNA analysis has been increasingly important in forensic science, forensic medicine, and paternity testing. Genetic variation can be detected by many DNA tests, including restriction fragment length polymorphism (RFLP) analysis, polymerase chain reaction (PCR), and DNA sequencing. Developments in the 1990s, such as more sensitive and discriminating PCR typing methods, the felon DNA databank, and increased governmental funding, have greatly enhanced the use of DNA in criminal investigations. See also Forensic chemistry; Forensic medicine.
1950
Artificial insemination of livestock using frozen semen is successfully accomplished
1952
Alfred Day Hershey and Martha Chase prove, on the basis of their bacteriophage research, that DNA alone carries genetic information
1953
James Dewey Watson and Francis Harry Compton Crick accurately describe the molecular structure of DNA
1953-4
Vincent du Vigneaud carries out the first laboratory synthesis of the peptide hormones oxytocin and vasopressin
1955
Severo Ochoa and M. Grunberg-Manago discover polynucleotide phosphorylase and successfully synthesize RNA
1956
Joe-Hin Tjio and Johan Albert Levan revise Walther Flemmings 1898 estimate of the human chromosome count from 24 pairs to 23
Arthur Kornberg discovers DNA polymerase I, which leads to the understanding of DNA replication
1956-8
Vernon Martin Ingram shows that normal and sickle-cell hemoglobin differ in a single amino acid residue in one of the chains
1957
Mahlon Bush Hoagland, Paul Charles Zamecnik, and M.L. Stephenson isolate transfer RNA and postulate its function
1958
Francis Harry Compton Crick enunciates the central dogma of molecular genetics, i.e., information flows from DNA to RNA to protein
1961
FranÐ*ois Jacob and Jacques Lucien Monod postulate the function of messenger RNA
1965
Genes conveying resistance to antibiotics in bacteria are found to reside on supersmall chromosomes called plasmids
1966
The genetic code is deciphered, thus demonstrating that a sequence of three nucleotide bases consisting of a codon determines each of 20 amino acids
1969
An enzyme is synthesized in vitro for the first time
1970
The first complete synthesis of a gene is accomplished
Howard Martin Temin and David Baltimore independently discover retroviruses–RNA viruses capable of reverse transcription, i.e., the synthesis of DNA from an RNA template
The first restriction enzyme is isolated
1972
The first recombinant DNA molecules are constructed using restriction enzymes and DNA ligase
The DNA composition of humans is discovered to be 99% similar to that of chimpanzees and gorillas
1973
Stanley Norman Cohen and Herbert Wayne Boyer demonstrate that restriction enzymes can be used to transfer genes from one species to another; recombinant DNA plasmids are successfully implanted in E. coli cells, thus demonstrating the possibility of cloning foreign genes