Average weight
of a DNA basepair (sodium salt) = 650 daltons
1.0 A260
unit ds DNA = 50 µg/ml = 0.15 mM (in nucleotides)
1.0 A260
unit ss DNA = 33 µg/ml = 0.10 mM (in nucleotides)
1.0 A260
unit ss RNA = 40 µg/ml = 0.11 mM (in nucleotides)
MW of a double-stranded
DNA molecule = (# of base pairs) X (650 daltons/base pair)
Moles of ends
of a 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)
1 µg of
1000 bp DNA = 1.52 pmol = 9.1 X 1011
molecules
1 µg
of pUC18/19 DNA (2686 bp) = 0.57 pmol = 3.4 X 1011
molecules
1 µg
of pBR322 DNA (4361 bp) = 0.35 pmol = 2.1 X 1011
molecules
1 µg
of M13mp18/19 DNA (7249 bp) = 0.21 pmol = 1.3 X 1011
molecules
1 µg
of l
DNA (48502 bp) = 0.03 pmol = 1.8 X 1010
molecules
1 pmol of 1000
bp DNA = 0.66 µg
1 pmol of pUC18/19
DNA (2686 bp) = 1.77 µg
1 pmol of pBR322
DNA (4361 bp) = 2.88 µg
1 pmol of M13mp18/19
DNA (7249 bp) = 4.78 µg
1 pmol of l
DNA (48502 bp) = 32.01 µg
1.0 kb DNA =
coding capacity for 333 amino acids @
37,000 dalton protein
10,000 dalton
protein @
270 bp DNA
50,000 dalton
protein @
1.35 kb DNA