In its early days, nick translation offered researchers a maximum specific activity of 40 percent incorporation. Today, companies such as Promega of Madison, Wis., advertise incorporation rates exceeding 60 percent. Amersham Pharmacia Biotech of Piscataway, N.J., and Roche Molecular Biochemicals of Indianapolis continue to offer nick translation kits but have optimized them for use with either radioisotopes or nonradioisotopic alternatives, to take advantage of the new labels now available. Likewise, Sigma-Aldrich of St. Louis offers its All-in-One™ Nick Translation Labeling Mix, which includes all of the necessary reaction components, including both enzymes and three dNTPs (omitting either dATP or dCTP) in a room-temperature, stable, quick-dissolving lyophilized solid for the production of either radioactive or nonradioactive probes. Other companies have abandoned their nick translation kits, citing a lack of support owing to competition from newer and arguably better methods.
One such method, random priming, was introduced in 1983 by Andrew P. ...