Maxam. Allan

Walter Gilbert and Allan Maxam at Harvard University devised a method for sequencing DNA using chemicals rather than enzymes. 

Most of the descriptions and procedures set out in this chapter are inevitably taken from, or based on, the published works of Maxam and Gilbert (1977, 1980) and Maxam (1979). The author is much indebted to Dr. Allan Maxam for permission to make extensive use of their protocols. Sufficient background and detail is included to undertake a sequencing project but it is strongly recommended that Maxam and Gilbert (1980) is consulted for further refinements and details. 

The year 1975 heralded DNA sequencing. Walter Gilbert (bom 1932) and Allan Maxam and Frederick Sanger (bom 1918) simultaneously develop different methods for determining the sequence of bases in DNA with relative ease and efficiency. 

Maxam and Gilbert Method. In 1977, Allan Maxam and Walter Gilbert developed a sequencing method that replaced the plus and minus method. This method was similar, as it required a radioactive label, gel electrophoresis for fragment separation, and the use of X-ray autoradiography for product visualization and inference of the sequence. However, the method differed in that it allowed for the direct analysis of purified double-stranded DNA and used another way of creating products ending in a specific nucleotide. 

Just after 1975, several methods for DNA sequencing were developed. Two of them, the chemical cleavage method of Allan Maxam and Walter Gilbert, and the chain terminator method of Frederick Sanger, are today used. The chemical cleavage method is explained below. 

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