MadSci Network: Molecular Biology Query:

The human genome is about 3 x 10 9 basepairs long, which would weigh about 40 pg (picograms: 1 pg = 10 -12 grams) per genome. Human cells are diploid, i.e. each contains two copies of the genome, so the nuclear DNA from a human cell would weigh about 80 pg. If we want total cellular DNA, then we need to include mitochondrial DNA (mtDNA). The human mitochondrial genome is about 16,000 basepairs long, there are about 10 copies of the genome per mitochondrion, and there are on the order of 1000 mitochondria per cell. This gives us about 0.2 pg of mtDNA per human cell. There are on the order of 10 14 cells per adult human, many of which are without nuclei, like skin cells and red blood cells. This would give us just under a kilogram of chromosomal DNA and on the order of a few grams of mitochondrial DNA in the average human body.

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