Use of 35S Nucleotides for DNA Sequencing

DNA sequencing is a technique that has become central to many laboratories engaged in molecular biology. The two basic sequencing methods commonly used are known as the Maxam-Gilbert method of chemical cleavage (1 ) and the dideoxy chain termination method developed originally by Sanger (2 ). One of the most critical steps in either of these two methods is the radiolabeling of the DNA such that the sequencing gel “ladder” of reaction products may be obtained after autoradiography of the sequencing gel.