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Megabase (Mb)

updated: May 10, 2022


A megabase (abbreviated Mb) is a unit of measurement used to help designate the length of DNA. One megabase is equal to 1 million bases. 



No, Megabase is not the name of a heavy metal rock band from the 1980s, as it may sound. A megabase is an extremely useful unit of measurement that can be helpful for understanding the scale of information contained in DNA.   For example, researchers can track the ever-decreasing cost of DNA sequencing by calculating the “cost per megabase of DNA sequence.”   In 2001, it cost about 5,292 dollars and 39 cents per megabase, which equaled about 95 million 263 thousand and 072 dollars per human genome.  By 2021, it cost only 0.006 dollars per megabase, which equaled about $562 per human genome.   What an enormous difference! This is due to incredible advances in technology and computational techniques, as well as knowledge gained from decades of sequencing human genomes.

Sarah A. Bates
Sarah A. Bates, M.S., M.A.

Chief, Office of Communications

National Human Genome Research Institute, NIH