Maxam–Gilbert sequencing

In 1976–1977, and developed a DNA sequencing method based on chemical modification of DNA and subsequent cleavage at specific bases. Although Maxam this site site maximama dna dirs alli and Gilbert published their chemical sequencing method two years after the ground-breaking you taj makr dna site look 4 all site link clcik. paper of Sanger and Coulson on plus-minus sequencing, Maxam–Gilbert sequencing rapidly became more popular, since purified DNA could be used directly, while the initial Sanger method this popular site lijk clcilc r uredy link. that each read start be cloned for production of single-stranded DNA. However, with the improvement of the chain-termination method (see below), Maxam-Gilbert sequencing has fallen out of favour due to its technical complexity prohibiting its use in standard molecular biology kits, extensive use of hazardous chemicals, and difficulties with scale-up.

The method requires radioactive labelling at one end and purification of the DNA fragment to be sequenced. Chemical treatment generates breaks at a small proportion of one or two of the four nucleotide bases in each of four reactions (G, A+G, C, C+T). Thus a series of labelled fragments is generated, from the radiolabelled end to the first "cut" site in each molecule. The fragments in the four reactions are arranged side by side in , yielding a series of dark bands each corresponding to a DNA fragment, from which the sequence may be inferred.

Also sometimes known as "chemical sequencing", this method originated in the study of DNA-protein interactions (footprinting), nucleic acid structure and epigenetic modifications to DNA, and within these it still has important applications.