What is the Difference Between Maxam Gilbert and Sanger Sequencing?

The Maxam-Gilbert and Sanger sequencing methods are two different techniques used for DNA sequencing. Here are the main differences between them:

1. Chemistry: The Maxam-Gilbert method depends on the relative chemical lability of different nucleotide bonds, whereas the Sanger method interrupts elongation of DNA sequences by incorporating dideoxynucleotides.
2. Radioactive labeling: Both methods rely on visualizing DNA fragments by radioactive labeling combined with gel electrophoresis and autoradiography.
3. Template requirements: The Maxam-Gilbert method can be performed with double-stranded DNA (dsDNA), while the Sanger technique requires cloning to produce single-stranded DNA (ssDNA) before sequencing.
4. Complexity: The Maxam-Gilbert method has a relatively complex setup and technical complexity, while the Sanger method is simpler and easier to perform.
5. Read length: The Maxam-Gilbert method has a shorter read length compared to the Sanger method.
6. Throughput: The Maxam-Gilbert method is low-throughput, while the Sanger method is more suitable for larger-scale sequencing projects.

Initially, the Maxam-Gilbert method was more widely used than the Sanger method due to its ability to work with dsDNA. However, with the introduction of new technologies and machinery, the Maxam-Gilbert method became less popular, and the Sanger method took over as the preferred method for DNA sequencing. Today, Maxam-Gilbert sequencing has been largely replaced by Sanger sequencing and next-generation sequencing methods, although it still has some niche applications.

Comparative Table: Maxam Gilbert vs Sanger Sequencing

Here is a table comparing Maxam Gilbert sequencing and Sanger sequencing:

Maxam Gilbert sequencing, also known as chemical sequencing, was the first DNA sequencing method introduced in 1976 by Walter Gilbert and Allan Maxam. It relies on breaking end-labeled DNA fragments using base-specific chemicals. On the other hand, Sanger sequencing, also known as chain termination sequencing or dideoxy sequencing, was developed by Frederick Sanger in 1977 and became more popular due to its efficiency, simplicity, and lower use of hazardous chemicals. The method involves using dideoxynucleotides (ddNTPs) to interrupt DNA synthesis. While Maxam Gilbert sequencing has its advantages, such as being suitable for analyzing nucleic acid structure and epigenetic modifications to DNA, it has several disadvantages, such as being technically complex, requiring extensive use of hazardous chemicals, and having a limited read length.