Nucleic Acid Data

Average weight of a DNA basepair (sodium salt) = 660 daltons

1.0A₂₆₀ unit ds DNA = 50µg/ml
1.0A₂₆₀ unit ss DNA = 33µg/ml
1.0A₂₆₀ unit ss RNA = 40µg/ml

MW of a double-stranded DNA molecule = (# of base pairs) X (660 daltons/base pair)
Moles of ends of double-stranded DNA molecule = 2 X (grams of DNA) / (MW in daltons)
Moles of ends generated by restriction endonuclease cleavage:
a) circular DNA molecule: 2 X (moles of DNA) X (number of sites)
b) linear DNA molecule: 2 X (moles of DNA) X (number of sites) + 2 X (moles of DNA)

1µg of 1000 bp DNA = 1.52pmol = 9.1 x 10¹¹ molecules
1µg of pUC18/19 DNA (2686bp) = 0.57 pmol = 3.4 x 10¹¹ molecules
1µg of pBR322 DNA (4361bp) = 0.35 pmol = 2.1 x 10¹¹ molecules
1µg of M13mp18/19 DNA (7250bp) = 0.21 pmol = 1.3 x 10¹¹ molecules
1µg of l DNA (48502bp) = 0.03 pmol = 1.8 x 10¹⁰ molecules