Maxam-Gilbert chemical sequencing method

Maxam, A. M. Gilbert, W. Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol. 1980, 65, 499-560. 

Determination of DNA Sequence Information. Almost all DNA sequence is determined by enzymatic methods (12) which exploit the properties of the enzyme DNA polymerase. Whereas a chemical method for DNA sequencing exists, its use has been supplanted for the most part in the initial determination of a sequence. Chemical or Maxam-Gilbert sequencing (13) is more often used for mapping functional sites on DNA fragments of known sequence. 

Figure 5-20. DNA sequencing by the Maxam-Gilbert method. End-labelled DNA is treated in four separate aliquots with chemical reagents which cleave specifically after A, G, C+Tand C. The fragments generated by partial chemical...

Small DNA segments can be synthesized in the laboratory, and commercial instruments are available for automating the work. Sequencing of DNA can be carried out either by the Maxam-Gilbert method, which uses chemical techniques, or by the Sanger dideoxy method, which uses enzymatic techniques. Small amounts of DNA can be amplified by factors of 10 using the polymerase chain reaction (PCR). 

Another sequencing technique is the Maxam-Gilbert method (developed by Alan Maxam and Walter Gilbert). In this method, a single DNA strand is labeled at the 5 end with radioactive phosphorus (P ). The radioactive DNA is divided into four portions and each one is exposed to different chemical reactions. Each reaction causes a 5 cleavage adjacent to either... 

---